Blackened Mahi Mahi Recipe

Combine paprika, onion powder, garlic powder, dried thyme, dried oregano, cayenne, black pepper and kosher salt in a small bowl. Mix thoroughly until uniform. Set aside.

Cook potatoes

Place peeled, cubed potatoes in a medium pot and cover with cold water by about 1 inch. Add a pinch of salt and bring to a boil over high heat. Reduce to a simmer and cook until potatoes are very tender, about 12–15 minutes.

Mash

Drain potatoes well and return to the hot pot for 1 minute to evaporate excess moisture. Add 2 tablespoons butter, 1/2 cup warm milk, 3/4 tsp salt and 1/4 tsp pepper. Mash to your desired texture (smooth or slightly rustic). Taste and adjust seasoning; keep warm while finishing fish and vegetables.

Preheat oven to 425°F (220°C). On a rimmed baking sheet, toss halved baby carrots and broccolini with 1 tablespoon olive oil, 1/2 tsp salt and 1/4 tsp black pepper. Arrange in a single layer.

Roast vegetables in the preheated oven until tender and lightly browned at the edges, 12–15 minutes. Keep warm when done.

Prepare fish

Pat mahi mahi fillets dry with paper towels. Brush each fillet lightly with 1/2 tablespoon melted butter (reserve remaining), then press both sides into the prepared blackening spice so each fillet is evenly coated. Let sit 5 minutes to adhere.

Preheat pan

Heat a large cast-iron or heavy skillet over medium-high heat until very hot. Add 1 tablespoon olive oil and swirl to coat.

Blacken mahi mahi

Place fillets in the hot skillet. Cook without moving for 3–4 minutes until a dark, charred crust forms and the edges begin to turn opaque. Flip carefully and cook 2–3 minutes more until internal temperature reaches 135–140°F (57–60°C) for moist fish (or cook to desired doneness). Remove fillets to a warm plate and tent with foil to rest.

Grill shrimp with rosemary

While fish rests, skewer two shrimp per serving (use metal or briefly soaked wooden skewers) and brush with remaining melted butter. Place a small rosemary sprig on the hot skillet (or directly under shrimp) to lightly char and release aroma. Add shrimp skewers and cook 1–2 minutes per side until pink and opaque and slightly charred, basting once with butter. Remove and place two shrimp on top of each mahi fillet.

Squeeze a little lemon over the assembled fish and shrimp, and garnish with the charred rosemary sprig.