Black Mirror Salmon and Tuna Nigiri

Great nigiri starts long before shaping, with the right fish and properly seasoned rice. Buy salmon labeled for raw eating and keep it on ice right up to the moment you slice it; cold fish cuts cleaner and tastes sweeter. Look for tuna with a clear, glassy red color and no rainbow sheen; a single even block is far easier to slice than trimmed pieces. Leftover components keep for a day in the fridge, but the finished dish is best eaten fresh.