The best part of this recipe is that you can prepare the fish the night before and let it marinate overnight before pulling it out to sear the next day. This'll save you a ton of time and leave less room for post-workout snacking while waiting for your dinner to cook.
Get creative with this one—try sprinkling cilantro or sesame seeds on top, or drizzling Sriracha mayo for added flavor.
Recipe and photo courtesy Amy at Chew Out Loud.
In a bowl, whisk together the first 7 ingredients to make a marinade. Towel-dry tuna steaks and place in a glass or ceramic dish. Pour marinade over the fish, turning to coat well throughout. Cover tightly, and chill several hours to overnight; turn fish over at least once in the middle of marinade time.
Heat 3 Tbsp oil in a large, heavy skillet (aluminum or stainless steel; not non-stick) until oil is smoking. Sear ahi steaks 1½ minutes per side on high heat, taking care to flip carefully with a flat, steel spatula. (If your tuna is less than 1½ inches thick, sear for only 1 minute per side.)
Transfer seared ahi to a large cutting board and let rest/cool 10 minutes. Use a very sharp (serrated works well) knife to slice thinly across the grain.
Serve chilled or at room temp, over your favorite salad greens. Sprinkle with sesame seeds and cilantro or green onions, if desired. Drizzle with Sriracha mayo if desired.