Instant Pot Mahi Mahi and Artichoke Sandwich

Mahi mahi has a firmness most white fish lack — dense enough to hold its shape through steam, moist enough to stay tender if that steam is gentle rather than aggressive. Instant Pot Mahi Mahi and Artichoke Sandwich uses the pressure cooker’s steam function rather than its high-pressure setting, cooking the fish and artichoke hearts together at a controlled, moderate temperature that takes minutes instead of the twenty or more a poach on the stovetop would need. What emerges is flaked into a bright, herb-forward filling, piled onto bread with a lemon aioli that ties the whole sandwich together.

This isn’t a dish that requires any special skill with the pressure cooker beyond understanding one distinction: steam, not high pressure, is what this fish wants.

Why This Recipe Works

Mahi mahi’s dense, meaty texture holds together well under moist heat, which makes it a strong candidate for steaming rather than a delicate fish like sole or flounder that would fall apart under the same treatment. Using the Instant Pot’s steam function — low pressure, gentle and even — cooks the fish through without the risk of drying it out the way direct high heat in a skillet might, since steam surrounds the fish evenly rather than concentrating heat on one surface.

Pairing the fish with artichoke hearts, steamed in the same basket, means both components finish together with minimal additional effort — the artichoke’s slightly vegetal, faintly nutty flavor rounds out mahi mahi’s own mild sweetness, while a lemon aioli spread on the bread adds the acidity and richness neither ingredient provides fully on its own.

Ingredients

• 1 lb mahi mahi fillets
• 1 cup canned or jarred artichoke hearts, drained and roughly chopped
• 1 cup water, for the Instant Pot
• 1 lemon, half sliced thin, half juiced
• 2 sprigs fresh dill, plus more chopped for serving
• 1/2 cup mayonnaise
• 1 small garlic clove, finely grated
• 4 sturdy sandwich rolls, split
• 1 cup baby arugula
• Salt and black pepper, to taste

Ingredient notes: Mahi mahi’s firm texture is specifically suited to this steaming method; a more delicate fish like tilapia or sole tends to break apart too easily when flaked after steaming. If mahi mahi isn’t available, halibut is the closest substitute in both texture and steaming behavior, though it typically costs more. Jarred artichoke hearts work well here and save real prep time; if using frozen artichoke hearts, thaw and pat them dry first, since excess moisture can dilute the finished filling’s flavor. The lemon aioli is a simplified version — mayonnaise doctored with garlic and lemon rather than a true emulsified aioli built from raw egg and oil — which keeps the process fast without sacrificing much in flavor.

How to Make It

1. Pour 1 cup water into the Instant Pot’s inner pot and insert a steamer basket or trivet. Lay the lemon slices in the bottom of the basket, then place the mahi mahi fillets on top, seasoned with salt and pepper. Scatter the artichoke hearts and dill sprigs around the fish.
2. Seal the lid and set the valve to sealing. Select the Steam function, or Pressure Cook on low, for 4 minutes — mahi mahi is a fast-cooking fish, and this brief window is enough to cook it through without drying it out.
3. Once the cook cycle ends, perform a quick release by carefully turning the valve to venting. Waiting for natural release adds unnecessary residual cooking time to fish that’s already delicate.
4. Open the lid once the pin drops. The mahi mahi should look fully opaque and flake easily with a fork at its thickest point; if any part still looks translucent, seal and steam for 1 additional minute rather than assuming it’s done.
5. Transfer the fish and artichoke hearts to a plate, discarding the lemon slices and dill sprigs. Flake the fish into large pieces with a fork, keeping some texture rather than shredding it fine.
6. While the fish cools slightly, whisk together the mayonnaise, grated garlic, and 1 tablespoon lemon juice in a small bowl. Taste and adjust with more lemon juice or a pinch of salt as needed.
7. Gently fold the flaked mahi mahi and chopped artichoke hearts together with a squeeze of the remaining lemon juice and the chopped fresh dill. Season with additional salt and pepper to taste.
8. Spread the lemon aioli generously on both cut sides of the rolls. Layer arugula on the bottom half, top with the mahi mahi and artichoke mixture, and close the sandwich. Serve immediately while the fish is still warm.

Key Techniques

Steaming rather than pressure-cooking the fish. The defining technique here is recognizing that mahi mahi needs gentle, low-pressure steam rather than the Instant Pot’s high-pressure setting typically reserved for tougher cuts of meat or dried legumes. High pressure applied to a delicate protein like fish drives out moisture too aggressively and can turn even a naturally firm fish like mahi mahi dry and stringy within seconds of overcooking. The Steam function, or a low-pressure setting held to a brief 4-minute window, cooks the fish through evenly without that risk. Success looks like opaque, moist flesh that separates into clean flakes under light pressure from a fork — not fish that shreds into fine, dry strands or resists flaking altogether, which signals undercooking.

Practical Cooking Tips

• Check your Instant Pot model’s steam settings before starting — some models default to a fixed steam time, while others let you set it manually; confirm you can hit the short 4-minute window this recipe needs.
• Make the lemon aioli first, while the Instant Pot comes up to pressure, so it has a few extra minutes to let the garlic flavor develop.
• Use a quick release rather than natural release without exception here — the few extra minutes of natural release add real risk of overcooking fish this delicate.
• Toast the rolls lightly if you have a moment; a slightly crisp interior surface holds up better against the aioli and the fish’s moisture than plain untoasted bread.

Common Mistakes and How to Avoid Them

• Using high pressure instead of the steam setting. This is the most common way this dish goes wrong — high pressure overcooks delicate fish quickly. Stick to the Steam function or low pressure for the short window specified.
• Using natural release. The extra residual time toughens and dries the mahi mahi. Always vent manually the moment the cycle ends.
• Overcrowding the steamer basket. If the fillets overlap, they cook unevenly. Arrange them in a single layer with some space, using two batches if your basket is small.
• Skipping the check for opacity. Pulling the fish before it’s fully opaque leaves a raw center. Check at the thickest point before assuming it’s done.

Variations and Substitutions

• Add capers to the filling: Their briny sharpness complements both the fish and artichoke without requiring any change to the cooking method.
• Swap dill for tarragon: Tarragon’s anise-like sweetness pairs classically with both fish and artichoke, offering a different but equally complementary herbal note.
• Make it spicier: A pinch of red pepper flakes stirred into the aioli adds background heat that plays well against the mild fish and vegetal artichoke.
• Serve open-faced: Skip the top half of the roll and serve the mixture over a single toasted slice for a lighter, knife-and-fork version of the same flavors.

How to Serve It

This sandwich works well for a light lunch, paired with a simple green salad dressed in lemon vinaigrette to echo the aioli’s brightness. It also holds up as a casual dinner option served alongside a cup of soup on a cooler evening. For entertaining, the fish and artichoke mixture can be prepared ahead and assembled into sandwiches just before serving, keeping the bread from turning soggy.

Storage and Reheating

Store the flaked mahi mahi and artichoke mixture separately from the aioli and bread in an airtight container in the refrigerator for up to 2 days — cooked fish has a narrower storage window than most proteins. This filling is best served cold or at room temperature rather than reheated, since reheating risks drying out fish that’s already been cooked once; if you do want it warm, heat gently in a covered pan over low heat for just a minute or two. Assemble sandwiches fresh each time rather than storing them pre-built, since the bread softens quickly once in contact with the aioli.

Approximate Nutrition Per Serving

Values are estimates only, based on standard ingredient data, and will vary with the specific bread and portion sizes used.

Closing Note

Instant Pot Mahi Mahi and Artichoke Sandwich takes a firm, mild fish and a pantry-friendly vegetable and gives them both a fast, gentle path to the plate — four minutes of steam, a quick flake, and a lemon aioli that pulls everything together. It’s a genuinely efficient use of a pressure cooker for something other than beans or stew. Set the timer, trust the quick release, and let the steam do the rest.