Blackened Mahi Tacos Recipe

Thinly slice 1/2 medium red onion into rings or half-moons and place in a heatproof jar or bowl.

In a small saucepan combine 1/2 cup apple cider vinegar, 1/4 cup water, 1 tsp sugar, 1/2 tsp kosher salt and optional 4 whole peppercorns. Heat just until the sugar and salt dissolve and the mixture is steaming (about 1–2 minutes).

Pour the hot brine over the sliced onion, pressing to submerge. Let cool to room temperature, then cover and refrigerate at least 20 minutes (can be made several hours ahead or overnight).

In a blender or food processor combine 1/2 cup mayonnaise, 1/4 cup packed cilantro leaves, 1 minced garlic clove, 1 tbsp fresh lime juice and 1/2 tsp lime zest.

Blend until smooth. Taste and add 1/2 tsp honey or agave if you want milder acidity, then season with 1/4 tsp kosher salt and 1/8 tsp black pepper. If desired, add 1/8 tsp smoked paprika for color. Chill until ready to use.

Pat 1 lb mahi-mahi dry with paper towels and cut into 4 evenly sized portions (about 4–5 oz each) to fit tortillas.

In a small bowl combine 1 tbsp smoked paprika, 1 tsp ground cumin, 1 tsp garlic powder, 1 tsp onion powder, 1/2 tsp dried oregano, 1/4 tsp cayenne pepper, 3/4 tsp kosher salt and 1/2 tsp black pepper. Mix well.

Lightly coat each fish portion with a thin film of oil or a little mayonnaise to help the seasoning adhere, then press the blackening seasoning onto both sides of the fish.

Heat a large cast-iron skillet or heavy pan over medium-high heat until very hot (about 3–4 minutes). Add 2 tbsp unsalted butter or high-heat oil and let it foam/melt.

Add the seasoned mahi and sear without moving for 2–3 minutes per side, until a dark crust forms and the fish reaches an internal temperature of about 135–140°F (opaque and flakey). Cooking time will vary by thickness.

Remove fish to a plate and squeeze 1 tbsp fresh lime juice over the fillets. Let rest 2 minutes, then flake into large chunks for assembly.

If using fresh homemade corn tortillas, warm them in a dry skillet over medium heat 20–30 seconds per side or wrap in a damp towel and microwave 20 seconds. Brush lightly with 1 tsp olive oil if you want a slightly toasted surface.

Toss 1 cup shredded green cabbage with 1/8 tsp salt and a squeeze of lime if desired to season lightly.

To assemble each taco: place a warmed tortilla on a plate, add a small handful (about 1/4 cup) of shredded cabbage, top with a portion of flaked blackened mahi (about 2–3 oz per taco), spoon 1–2 tbsp cilantro-lime aioli over the fish, add 1–2 tbsp quick pickled red onions, and finish with a sprinkle of fresh cilantro leaves.

Serve two tacos per person with lime wedges on the side. Leftover aioli and pickled onions keep in the fridge for several days.