Stuffed Swordfish and Radicchio Pho

Pho broth carries the memory of everything that built it. Star anise, charred ginger, cinnamon bark — these are not seasoning additions but structural decisions, aromatics that slowly surrender their character into the liquid over the course of an hour and emerge as something unified and deep. Introducing swordfish to that broth changes the conversation. Swordfish is a meaty, firm-fleshed fish with a mineral savoriness that holds its own against the complexity of the broth rather than disappearing into it. Stuffed with a tightly seasoned herb and lemongrass mixture before going in, the fish becomes a distinct element within the bowl — something to discover, slice through, and eat against the bitter curl of radicchio that wilts just enough in the hot liquid to lose its harshness without losing its color.

Stuffed swordfish and radicchio pho is not a traditional preparation, and it does not pretend to be. It is a dish built from pho’s foundational logic — a deeply aromatic broth that organizes every element around itself — applied to ingredients that reward that treatment in a different register entirely.

Why This Recipe Works

The broth is the organizing principle. Pho broth achieves its signature depth through two mechanisms: the charring of aromatics (ginger and onion are typically blackened directly over flame before being added to the pot) and the long extraction of collagen and gelatin from bones or, in this fish version, from a concentrated fish stock. Charring creates bitter, caramelized compounds at the aromatics’ surface that dissolve into the broth and give it a roasted, almost smoky undertone that raw aromatics cannot produce. In this recipe, that step is non-negotiable — it is what separates a complex broth from a spiced stock.

Swordfish is selected for structural reasons. Its flesh is dense enough to be stuffed and poached without falling apart — a quality that halibut shares but most delicate white fish do not. The lemongrass and herb stuffing inside the swordfish cross-section functions as a flavor anchor: the heat of the broth extracts the stuffing’s aromatics and they bleed gently into the surrounding liquid, creating a graduated flavor around the fish that enriches each spoonful of broth taken nearby.

Radicchio is a deliberate choice over the more common bean sprout or bok choy. Its bitterness, which is sharp when raw, softens in hot broth to something that reads as pleasantly vegetal and slightly sweet — a counterweight to the richness of the swordfish and the sweetness of the star anise. It also holds its magenta color far longer than softer greens, making the bowl visually coherent through the full duration of the meal.

Ingredients

Quantities are for 4 servings. The broth can and should be made ahead — it improves significantly after 24 hours in the refrigerator.

For the Pho Broth

• 1.5 liters (6 cups) good fish stock, unsalted — the quality of the stock determines the ceiling of this dish. Homemade is strongly preferred; store-bought concentrates can be used but tend toward saltiness that limits seasoning control at the end.
• 1 large white onion, halved — to be charred.
• 1 large piece of fresh ginger (about 8cm / 3 inches), unpeeled — to be charred alongside the onion.
• 3 whole star anise
• 1 cinnamon stick
• 4 whole cloves
• 1 tablespoon coriander seeds, lightly toasted
• 2 tablespoons fish sauce — the primary seasoning vehicle. Use a good-quality Thai or Vietnamese fish sauce; avoid brands with added sugar as a first ingredient.
• 1 teaspoon coconut sugar or palm sugar — balances the fish sauce’s salinity without sweetening the broth perceptibly.
• 1 tablespoon fresh lime juice — added at the end, not during cooking. Acid added during the simmer will dull the broth; acid added just before serving brightens it sharply.

For the Stuffed Swordfish

• 4 swordfish steaks, 3–4cm (about 1.5 inches) thick — ask your fishmonger to cut them thick; thinner steaks will not hold the stuffing pocket without tearing. Tuna or mahi-mahi can substitute; both have similar density but slightly different flavor profiles.
• 2 stalks lemongrass, inner core only, very finely minced
• 3 tablespoons fresh cilantro, finely chopped
• 2 tablespoons fresh mint, finely chopped
• 2 garlic cloves, grated on a microplane
• 1 teaspoon fresh ginger, grated
• 1 tablespoon fish sauce
• 1/2 teaspoon white pepper
• 1 tablespoon neutral oil — for searing the exterior before poaching.

For the Bowl

• 200g (7 oz) dried rice noodles, flat — prepared according to package directions before assembly. Banh pho noodles (3–5mm width) are the standard; thicker noodles overwhelm a fish broth.
• 1 small head radicchio, leaves separated and roughly torn
• 4 scallions, thinly sliced on the diagonal
• Fresh Thai basil, cilantro, and mint for garnish
• Lime wedges, sliced fresh chili, and additional fish sauce — at the table for individual adjustment.

How to Make Stuffed Swordfish and Radicchio Pho

1. Char the aromatics. Place the halved onion and ginger cut-side down directly over a gas burner on high flame, or under a preheated broiler on a foil-lined sheet pan. Char until deeply blackened on the cut surfaces — 8–10 minutes. The exterior should look burnt; this is correct. Rinse briefly under cold water and rub off the loosest char, but leave significant blackening. Set aside.
2. Build the broth. Combine the fish stock, charred onion and ginger, star anise, cinnamon, cloves, and toasted coriander seeds in a large pot. Bring to a gentle simmer over medium heat — never a rolling boil, which clouds the broth and drives off delicate aromatics. Simmer uncovered for 35–40 minutes. The broth should deepen in color and aroma. Strain through a fine-mesh sieve, pressing the solids lightly. Return to the pot. Add the fish sauce and coconut sugar. Taste: the broth should be savory, slightly sweet, and fragrant with star anise. Hold warm over low heat.
3. Make the stuffing. Combine the minced lemongrass, cilantro, mint, garlic, ginger, fish sauce, and white pepper in a small bowl. Mix thoroughly — the mixture should be moist but not wet, dense enough to hold a shape when pressed. If it seems too loose, add a tablespoon of finely minced scallion to absorb the excess moisture.
4. Stuff the swordfish. Using a thin, sharp knife, cut a deep horizontal pocket into each swordfish steak — the opening should be narrow (about 3cm across) but extend as far into the steak as possible without breaching the opposite side or the top. Spoon the stuffing firmly into each pocket, pressing it to the back. The pocket will stretch slightly. Do not overfill — the stuffing should be compact inside, not forcing the seam open. Pat the exterior of each steak dry with paper towels.
5. Sear the swordfish. Heat a heavy skillet over high heat. Add the neutral oil and sear each stuffed steak for 90 seconds per side until a pale golden crust forms on the exterior. The fish should not be cooked through at this stage — the sear is for surface structure and flavor, not doneness. Transfer to a plate.
6. Poach the swordfish in the broth. Bring the strained broth to a gentle simmer (around 85°C / 185°F — the surface should tremble with small bubbles, not roll). Lower the seared swordfish steaks into the broth carefully. Poach for 6–8 minutes, turning once gently at the halfway point, until the flesh is just opaque through to the center when tested with a thin knife. Do not let the broth boil during poaching — a boil breaks the fish apart and turns the texture chalky. Remove the fish gently with a slotted spatula and set aside. Add the lime juice to the broth and taste for seasoning.
7. Prepare the noodles and radicchio. Divide the softened rice noodles among four wide, deep bowls. Place a few torn radicchio leaves over the noodles — they will wilt in the hot broth but should not be pre-wilted.
8. Assemble and serve. Ladle the hot broth generously over the noodles and radicchio in each bowl. Place one stuffed swordfish steak into each bowl, partially submerged. Scatter scallions over the top and add the fresh herb garnishes. Serve immediately with lime wedges, sliced chili, and fish sauce on the side.

Key Techniques

Charring Aromatics for Pho Broth

The charring step is the technical foundation of this broth and the point where most home cooks pull back too early. True charring requires genuine blackening — not browning, not caramelizing, but a carbonized surface that looks, on its face, like something has gone wrong. The compounds created at this stage — particularly pyrazines and furans — are what give pho broth its characteristic depth and slight smokiness. They are not extractable through any other method. A lightly browned onion added to the broth produces a categorically different result, noticeably thinner in aroma and rounder in a way that lacks the broth’s signature edge. Commit to the char.

Poaching Fish at Sub-Boil Temperature

The distinction between a simmer and a boil matters more with fish than with almost any other protein. Fish proteins begin to contract and expel moisture rapidly above 85°C (185°F). A boiling broth maintains temperatures well above that threshold and produces fish that is simultaneously overcooked and waterlogged — the opposite of what poaching should achieve. The visual target is a surface that shivers rather than churns: small, infrequent bubbles breaking the surface from below, steam rising consistently. At this temperature, the fish cooks gently and retains both its moisture and its structural integrity. A thermometer is the most reliable tool, but the visual cue of a quivering surface is precise enough once recognized.

Practical Cooking Tips

• Make the broth the day before. Refrigerating overnight allows fat to solidify on the surface for easy removal and allows the spice profile to integrate and mellow. A fresh broth often reads as slightly sharp and one-dimensional; a rested one is noticeably more cohesive.
• Keep the stuffing cold until you use it. Warm stuffing in a room-temperature fish pocket is a food safety concern and also causes the fish to begin cooking at the surface during the searing step, before you intend it to. Refrigerate the stuffing after mixing and stuff the fish no more than 15 minutes before searing.
• Wide, deep bowls are not optional. The stuffed swordfish steak needs to sit partially submerged in broth — a shallow bowl forces you to plate them sitting on top of the noodles, which causes the fish to press down and break the stuffing pocket open. Choose bowls with a depth of at least 8cm.
• Add lime to the broth at the last moment, not during simmering. Citric acid that cooks for any length of time loses its bright top note and leaves behind a flat sourness. The same principle applies to the lime wedges at the table — they are there for individual finishing, not bulk adjustment.

Common Mistakes and How to Avoid Them

Under-charring the aromatics. The most common mistake in home pho is pulling the ginger and onion from the flame before genuine char develops. If the cut surface is golden-brown, it has not gone far enough. The result is a broth that is pleasant but lacks the structural depth the charring compounds provide. Go further than feels comfortable.

Boiling rather than poaching the fish. This produces chalky, overcooked swordfish that falls apart in the bowl and releases its stuffing into the broth prematurely. Once the swordfish is in the pot, reduce the heat before it enters and do not increase it. The fish will still cook through — it simply takes a few minutes longer at the correct temperature.

Watch this: Swordfish continues cooking in the hot broth after it has been removed from the heat source. Pull the steaks from the broth when the center still shows the faintest translucency — carryover will finish the job in the 90 seconds it takes to ladle the broth and assemble the bowls. Fish that is fully opaque when it leaves the pot will be overcooked by the time it is eaten.

Stuffing the fish too tightly. A pocket forced full of stuffing cannot expand as the fish cooks and will split open along the seam, releasing the filling into the broth before it has had time to contribute its aromatics from inside the fish. Fill firmly but stop short of the point where the opening begins to gape.

Variations and Substitutions

Replace radicchio with endive for a slightly more delicate bitterness and a less visually assertive bowl. Endive wilts more quickly than radicchio; add it at the very last moment before ladling the broth.

For a richer stuffing, add a tablespoon of finely minced shrimp to the lemongrass-herb mixture. The shrimp binds the stuffing more cohesively and adds a subtle sweetness that reinforces the star anise in the broth. Ensure it is finely chopped — visible shrimp pieces in the stuffing can create uneven cooking.

Shiitake mushrooms added to the broth during the final 10 minutes of simmering contribute glutamates that amplify the umami of the fish sauce and give the broth additional body without changing its fundamental character. Slice them thinly and leave them in the broth rather than straining them out — they are worth eating.

A black pepper and makrut lime leaf variation in the stuffing — replacing the white pepper with cracked black pepper and adding two finely chiffonaded makrut lime leaves — shifts the aromatic profile of the fish toward something more citrus-forward. This variation pairs particularly well if you are serving the pho in warmer months when the lighter, brighter notes read more naturally.

How to Serve It

Stuffed swordfish and radicchio pho is a composed bowl that requires table presence to be fully appreciated. Serve it with the herb plate, lime wedges, sliced fresh chili, and a small dish of fish sauce on the side — pho is customized at the table, and the personal calibration of acidity, heat, and saltiness is part of the experience. Set everything out before the broth is ladled so the bowls can go to the table immediately while the broth temperature is at its peak.

This dish suits a dinner party context particularly well — it is visually striking, the broth can be made entirely ahead, and the assembly is fast enough that four bowls can be plated in under three minutes once the fish is poached. A cold starter with bright acidity — a thin-sliced cucumber salad dressed with rice vinegar and sesame — works well before the bowl without competing with the broth’s spice profile.

Storage and Reheating

The broth stores separately from all other components and keeps for up to four days in the refrigerator or three months frozen. Reheat gently over medium-low heat — never at a full boil, which dulls the spice notes. Add the lime juice fresh when reheating, not from the original batch.

Cooked swordfish stored in the broth will continue to cook slightly from residual heat and will be perceptibly firmer when cold. For leftovers, store the fish separately from the broth in a sealed container for up to two days. To reheat, lower the fish into the gently warmed broth for 2–3 minutes — do not microwave, which dries the exterior before the interior warms through.

Noodles should always be prepared fresh. Day-old rice noodles absorb broth and swell into a gummy texture that no reheating method corrects. Prepare only what you need for immediate serving.

Approximate Nutrition Per Serving

All values are approximate estimates for informational purposes only. Calculated for one full bowl including swordfish, noodles, broth, and radicchio. Values vary based on noodle quantity and fish size.

Stuffed swordfish and radicchio pho asks more of a cook than most bowl dishes do — the broth requires patience, the stuffing requires precision, and the poaching requires restraint. What it returns for that investment is a bowl with genuine depth at every level: a broth that took an hour to build, a fish that carries its own aromatics inside it, and a bitter green that holds its ground against both. This is the kind of recipe that improves with repetition, and the kind of dish that makes the learning worth it.

Set aside a Sunday afternoon for the broth, and the rest follows quickly enough.