Serves 4  ·  Ready in 60 min  ·  Plant-Based

A vegetarian pho built on charred aromatics, whole spices, and grilled tempeh — where the broth carries the dish and every component earns its place through function, not convention.

Pho Without Bones: The Challenge and the Solution

Traditional pho is an extraction dish. Its broth achieves depth through hours of bone simmering, which releases collagen, gelatin, and marrow fat — compounds that give the soup its characteristic body and the way it coats the palate. A vegetarian version that simply replaces the bones with vegetables produces something thin and flat, no matter how long it simmers. The flavors are there, but the structure is missing.

Grilled Tempeh Pho with Carrots solves this structurally rather than through substitution. The broth is built on charred ginger and onion — the technique pho uses whether or not it contains meat — plus a toasted whole-spice blend that contributes fat-soluble aromatic compounds that water alone cannot extract efficiently. Kombu provides glutamates that approximate the savory depth bone marrow provides. The result is a broth with genuine backbone: fragrant, slightly sweet from the charring, and savory in a way that makes the bowl feel complete. The grilled tempeh — pressed, marinated, and charred on a grill pan — provides protein, textural resistance, and the Maillard-reaction bitterness that contrasts with the broth’s warmth. The carrots are not background filler; they are cooked separately to retain their sweetness and structural integrity, adding color and a clean crunch that the soft noodles and tender tempeh require as counterpoint.

The Technique Behind It

Pho broth is built on two sequential processes: direct-heat charring followed by aromatic infusion. Charring the onion and ginger halves — cut-side down over a gas flame or under a broiler until genuinely blackened at the surface — does two things simultaneously. It drives off the harsh, sulfurous volatile compounds in the onion that would make the broth taste raw, and it generates Maillard reaction products: hundreds of flavor compounds including pyrazines and furans responsible for roasted, nutty, complex notes. These cannot be created through gentle simmering; they require temperatures above 140°C (285°F) and direct contact with a heat source.

The spice bloom that follows — toasting star anise, cinnamon, cloves, and coriander in a dry pan before adding water — exploits the fat-soluble nature of their aromatic compounds. Briefly heating the spices opens their cell structure and volatilizes essential oils that would otherwise dissolve slowly and incompletely into water. A two-minute toast in a dry skillet extracts more aromatic depth than thirty minutes of gentle simmering from untoasted spices.

Grilling the tempeh introduces the dish’s structural counterpoint. Tempeh is a fermented soy product with a firm, porous matrix that absorbs marinades efficiently and develops a defined crust under high direct heat. Unlike tofu, which must be pressed at length to remove water before searing, tempeh’s fermentation process has already created a relatively dry, dense structure. It grills with minimal preparation and holds its shape in the broth without disintegrating.

Ingredients — Serves 4

On substitutions

Kombu: If unavailable, add 1 tbsp of white miso stirred in off the heat at the end — it provides a comparable glutamate hit, though with a slightly different aromatic profile. Do not simmer the miso; it turns bitter under sustained heat.

Tempeh: Extra-firm tofu, pressed for 30 minutes and sliced 1.5 cm thick, can substitute. It will not develop the same crust density as tempeh because its water content is higher even after pressing — expect a softer exterior and a more neutral flavor. The marinade and grill technique remain identical.

Carrots: Daikon radish, cut identically, is the more traditional pho choice and has a sharper, slightly bitter note that contrasts more aggressively with the sweet broth. Both work; the flavor register is different.

How to Make It

1. 1 Soak the noodles. Cover the dried rice noodles in cold water and soak for 30 minutes. They should become pliable and slightly opaque but not fully soft — they will finish cooking in the hot broth at serving time. Drain and set aside. Soaking rather than boiling prevents the noodles from becoming mushy when the hot broth is poured over them.
2. 2 Char the onion and ginger. Set a gas burner to high or position your oven rack directly under the broiler. Place the onion halves and ginger halves cut-side down directly over the flame or on a foil-lined tray under the broiler. Char for 5–7 minutes until the cut faces are deeply blackened and beginning to soften. The exterior char is intentional; it contributes roasted sweetness to the broth. Set aside.
3. 3 Toast the spices. In a dry skillet over medium heat, combine the star anise, cinnamon stick, cloves, and coriander seeds. Toast, shaking the pan constantly, for 90–120 seconds until fragrant and slightly darkened. The moment you smell a sharp, almost smoky spice aroma, remove from heat immediately. Overtoasted spices become bitter. Transfer to a large pot.
4. 4 Build the broth. Add the charred onion and ginger, the kombu, cold water, soy sauce, sugar, and salt to the pot with the toasted spices. Bring to a boil over high heat, then reduce to a low simmer — small bubbles breaking the surface occasionally, not a rolling boil. A hard boil clouds the broth and drives off the volatile aromatic compounds you just created through charring. Simmer uncovered for 45 minutes.
5. 5 Marinate the tempeh. While the broth simmers, whisk together the soy sauce, sesame oil, rice vinegar, and grated ginger. Add the tempeh slices and turn to coat. Marinate for at least 20 minutes at room temperature — the acidity in the rice vinegar opens the tempeh’s surface and allows the marinade to penetrate rather than just coat the exterior.
6. 6 Cook the carrots. Bring a small saucepan of salted water to a boil. Add the carrot pieces and cook for 3–4 minutes — they should be tender at the center but still have faint resistance when pressed between your fingers. Drain and set aside. Fully soft carrots will turn mushy when the hot broth hits them; slight undercooking is correct here.
7. 7 Grill the tempeh. Heat a cast iron grill pan over high heat for 2 minutes. Brush with neutral oil. Remove the tempeh from the marinade — do not pat dry; the residual marinade on the surface will caramelize during grilling and form the crust. Grill the slices for 3–4 minutes per side without moving them until defined grill marks appear and the surface is dry and slightly charred at the edges. Do not press down on the tempeh — it compresses the interior and forces out moisture, which steams the surface rather than searing it.
8. 8 Strain the broth. After 45 minutes, strain the broth through a fine-mesh sieve into a clean pot, pressing the solids lightly. Discard the aromatics. Taste the broth now — it should be savory, lightly sweet from the charred onion, and deeply spiced. Adjust with additional soy sauce for salt, sugar for sweetness, or a squeeze of lime juice for brightness. The broth should be seasoned assertively; dilution from the noodles and toppings will moderate it in the bowl.
9. 9 Assemble. Divide the soaked noodles among four deep bowls. Ladle the broth over the noodles — the hot liquid will finish cooking the noodles in about 90 seconds. Add the carrot pieces and grilled tempeh slices. Bring the garnish plate to the table and let each person add their own sprouts, herbs, chili, and condiments.

Getting the Broth and the Grill Right

The char: knowing when to stop

The charred onion and ginger are the broth’s flavor foundation, and the degree of char determines whether the broth tastes complex and roasted or bitter and acrid. The target is a cut face that is black in patches — 60 to 70% blackened — with the remaining surface dark brown. The interior of the onion should still feel firm when pressed; if it has fully softened and turned translucent all the way through, the char has gone too long and the sulfur compounds have fully cooked out, leaving something muted rather than roasted. Five to seven minutes over direct high heat achieves the correct result. Any longer and the char migrates inward and the bitterness follows it into the broth.

The tempeh grill: the release is the signal

Tempeh that is properly marinated and placed on a correctly preheated grill pan will stick initially — this is normal and indicates the Maillard reaction is occurring at the contact surface. The instinct to move or lift the tempeh before the crust has formed leads to tearing and lost surface area. Leave each slice undisturbed for the full 3–4 minutes. When the crust has set completely, the tempeh will release cleanly from the pan with a gentle lift of a thin spatula. If it resists, it is not ready. Forcing it off destroys the crust and exposes the soft interior, which will not develop further grill marks or texture on the second side.

Troubleshooting

Broth tastes flat and watery despite the aromatics

The spices were not toasted before simmering, or the simmer was too aggressive and drove off the volatile aromatic compounds before they could dissolve into the broth. Toast the spices first, every time — there is no workaround for skipping this step. If the broth is already made and tastes thin, toast a fresh set of spices, add them to the finished broth, and simmer for an additional 15 minutes. Add a teaspoon of white miso off the heat to reinforce the savory base.

Broth is bitter

The onion or ginger charred too long, or the spices were over-toasted. Bitterness from over-charred onion is difficult to correct — a small amount of sugar helps, but it masks rather than removes the problem. A squeeze of lime juice and a tablespoon of coconut sugar can partially round the edges, but if the bitterness is pronounced, it is faster to remake the broth with properly charred aromatics.

Noodles are mushy before the broth is poured

They were soaked too long, or in water that was too warm. Rice noodles continue softening as long as they are in contact with water. Soak in cold water and check at 25 minutes — they should bend without cracking but feel firm between your fingers. Drain immediately and hold dry. If they have over-soaked, they will not survive hot broth without turning to paste; start with a fresh batch of noodles.

Tempeh sticks and tears on the grill pan

The pan was not hot enough before the tempeh was added, or the tempeh was moved too early. A grill pan must be preheated over high heat for a full 2 minutes before oiling — test by holding your hand 5 cm above the surface; you should feel strong radiating heat immediately. If the pan is underheated, the marinade pools and steams rather than caramelizing, and the tempeh sticks permanently rather than releasing when the crust forms.

Variations Grounded in Culinary Logic

Roasted mushroom broth addition

Add 200 g (7 oz) of dried shiitake mushrooms to the broth during the 45-minute simmer. Shiitakes are exceptionally high in glutamates and guanylates — flavor compounds that are synergistic with the glutamates already contributed by the kombu, multiplying savory depth non-linearly. The resulting broth will be noticeably fuller-bodied without tasting of mushrooms specifically. Strain them out with the other aromatics.

Charred scallions in the broth base

Add four whole scallions, charred alongside the onion and ginger, to the broth. Scallions contribute a more vegetal, grassy note than yellow onion and a sharper allium character that brightens the final broth. This variation works well if the spice blend is kept lighter — reduce the star anise to two pieces so the scallion’s contribution is not overwhelmed.

Marinated carrots instead of blanched

Julienne the carrots finely and marinate them for 30 minutes in 2 tbsp rice vinegar, 1 tsp sugar, and a pinch of salt. They won’t be cooked — they contribute raw crunch and acidity rather than the soft sweetness of blanched carrots. This version makes the bowl lighter and more acidic overall, which suits a spicier broth well. Add the pickled carrots at serving time rather than into the hot broth.

Coconut broth variation

Add 200 ml (¾ cup) of full-fat coconut milk to the strained broth and heat gently — do not boil, which would break the emulsion and leave floating fat globules. The coconut milk rounds the spice profile considerably, softening the star anise and cinnamon into something more aromatic than sharp. This version leans toward a laksa-adjacent flavor, which pairs well with tempeh’s slightly bitter, fermented character. Reduce the soy sauce by half to compensate for the added richness.

Serving and Pairing

Pho is designed to be finished at the table — the garnish plate is not optional decoration. Bean sprouts provide raw crunch that contrasts with the soft noodles; they also lower the broth temperature, which concentrates the aroma at the surface and makes the bowl more fragrant as you eat. Fresh Thai basil introduces a clove-anise note that echoes the star anise in the broth without duplicating it. Lime juice, squeezed directly into the bowl, sharpens the broth’s savory edge and makes the spices more legible.

Hoisin sauce and sriracha serve different functions: hoisin adds sweetness and a thick, almost lacquer-like richness when stirred in; sriracha adds vinegar-forward heat without the smokiness of dried chili. Neither should be added before tasting — the broth of Grilled Tempeh Pho with Carrots is already seasoned and the condiments should be used as personal calibration, not as corrections to an under-seasoned bowl.

Serve in the deepest bowls you own. Shallow bowls cool pho too quickly and reduce the surface from which the aromatics volatilize. The first few minutes of a properly assembled bowl — when the broth is still at near-boiling and the herbs are wilting slightly at the edges — are the best minutes, and the bowl should be designed to extend them.

Storage and Reheating

Store the broth, noodles, tempeh, and carrots separately. The broth keeps refrigerated for up to 5 days and improves over the first 48 hours as the spice infusion deepens and integrates. After day three, the star anise begins to dominate — the balance shifts. Reheat the broth to a full simmer before serving; partial reheating leaves it under-temperature and the aromatics do not volatilize properly.

Noodles stored in broth will absorb it and become swollen and mushy within two hours. Store them dry in a sealed container, separate from the broth, and soak briefly in hot water for 60 seconds to refresh before assembling the next bowl. The carrots hold well for 3 days refrigerated; reheat them briefly in the hot broth for 30 seconds rather than separately. The grilled tempeh keeps for 3 days and reheats best in a dry skillet over medium heat for 2 minutes per side — this restores some crust without drying the interior. Microwaving softens the crust completely and is not recommended.

The broth freezes well for up to 3 months. Freeze it in portion-sized containers so you can reheat individual servings without cycling the full batch through temperature changes multiple times.

Approximate Nutrition Per Serving

All values are approximate estimates for informational purposes only. Actual values vary based on specific ingredients, brands, and portion sizes.

What Grilled Tempeh Pho with Carrots teaches is that depth in a broth is not a function of time alone — it is a function of technique applied at the right moment. Charring before simmering, toasting before steeping, grilling before serving: each of these is a deliberate intervention in how flavor develops, and each produces a result that the passive approach cannot replicate. A cook who understands these mechanisms will apply them instinctively in other contexts — in soups built on entirely different traditions, in broths that contain no trace of this dish’s DNA.

Pho is, at its core, a lesson in extraction and contrast. This version happens to contain no meat — but it makes no compromises on the principles that make the dish worth understanding.