black sesame encrusted seared ahi tuna with ponzu reduction

I don't remember my first raw fish. I remember some but not the first. Gentle breezes laced with salt air, the sun on my back, wind blowing through palm trees sounding like an echo of  the ocean. There are thick slices of tuna and salmon haunting vinegared rice and covered with toasted nori. I eat them in gulps my classmates nudge me. Ew, that's raw fish, they say, and I suddenly swallow, uneasy. But the taste remains, that fresh, clean taste. Pure and unadorned. 

Ahi tuna is one of those few fish, like swordfish, that's really more of a hearty meat than others like cod. The bright pink flesh is sliced into half-inch or inch thick steaks and carefully wrapped in paper, ready for you to slip in your canvas bag and take home. How do you honor a fish both mild in flavor and robust enough for any cooking technique? The sheer heartiness of it provides an answer as tuna stands up well to a simple sear, so close to being left raw. I like to coat mine in sesame seeds to provide a crunchy contrast.

Every good meal deserves a good sauce. Here, I'm drawn toward the flavors of my childhood in Hawaii. Soy sauce mixed with a fruit acid (lime here) and the taste of Chinese black vinegar thick with five spice and a dusting of star anise. Reduce this over a low heat until au sec and nappe (nearly dry and when you coat the back of a spoon, you can draw your finger through it and the line stays.) .

1 5-6 oz ahi tuna steak
1/2 cup black sesame seeds
1/2 cup soy sauce
2 tbsp lime juice
2 tbsp Chinese black vinegar
1 oz canola oil

On a plate, spread out the sesame seeds. Flip tuna steak around until evenly coated. In a 10" saute pan heat oil until nearly smoking. Add the fish and sear for approximately two minutes on either side. Remove. 

In a small saucepan, combine soy sauce, lime juice, and vinegar. Reduce until sauce has thickened, about halfway. Drizzle tuna with sauce. Serve.