Seared Ahi Tuna Recipe

Make the compound butter

In a medium bowl, combine the softened butter, minced jalapeño, chopped capers, lemon zest, lemon juice, chopped parsley, salt, and black pepper. Mix thoroughly until evenly distributed. Transfer the butter onto a piece of plastic wrap or parchment, shape into a log about 1" in diameter, wrap tightly and chill in the refrigerator at least 30 minutes to firm up (can be made up to 2 days ahead).

Cook the vegetables

Heat 1 tablespoon olive oil and 1 tablespoon butter in a large skillet over medium-high heat until shimmering. Add the sliced mushrooms and cook undisturbed 2 minutes to brown, then add zucchini and red bell pepper. Sauté, stirring occasionally, until vegetables are tender-crisp, about 4–5 minutes. Add the sliced garlic during the last 30–45 seconds and cook until fragrant but not browned. Stir in 1 teaspoon soy sauce, 1/2 teaspoon salt and 1/2 teaspoon freshly ground black pepper. Remove from heat and keep warm.

Prepare the tuna

Pat tuna steaks dry with paper towels. Season both sides with 1 teaspoon kosher salt and 1 teaspoon freshly ground black pepper, pressing gently to adhere.

Sear the tuna

Heat a heavy skillet (cast iron preferred) over high heat until very hot. Add 2 tablespoons olive oil and swirl to coat. When oil is shimmering and just smoking, place tuna steaks in the pan, leaving space between them. Sear without moving: 30–45 seconds per side for rare (center warm and bright pink), 60–75 seconds per side for medium-rare. Avoid overcooking; tuna should have a nicely browned exterior and raw-to-rare center. If steaks are thick (1"+), you can also sear edges 15–30 seconds. Remove steaks to a plate and tent loosely with foil for 1–2 minutes.

Finish with jalapeño caper butter

Slice the chilled jalapeño caper butter into 4 rounds. Place one round on top of each seared tuna steak; the butter will melt slightly from the residual heat. If you prefer the butter more melted, return the skillet to medium-low, place tuna back in for 30 seconds with butter on top, then remove.

Divide the choice of side (rice, mashed potatoes or greens) among 4 plates. Arrange a portion of the sautéed vegetables next to the side. Place a seared tuna steak on each plate, topped with the jalapeño caper butter. Scatter extra capers over the butter if using and garnish with microgreens or chopped parsley. Serve with lemon wedges on the side for squeezing over the fish.