This is the ahi dish on nearly every local restaurant menu — a block of sashimi-grade tuna rolled in furikake and sesame seeds, seared hard and fast on the outside, left cool and rare in the middle. It's less a recipe than a technique: get the fish good, get the pan hotter than feels reasonable, and don't overcook it.
The wasabi cream or ponzu on the side is doing a lot of work, but really this dish is about the contrast — crunchy, savory crust against cool, silky raw tuna.
