Zuke Don, it is marinated tuna on a bowl of rice. By marinating, the tuna meat gets juicier and its Umami is enhanced.
1/3 Ib Sashimi quality Tuna meat
1 T Soy sauce
1 T Sake
1/2 T Mirin
1 t Sesame Oil
1. Marinate Tuan meat in the sauce for 1 hour or two.
2. Place Tuna on rice, pour the sauce and top with Sesame and Wasabi.
Shiso (Perilla leaves) adds nice touch.