Mix the soy sauce and wasabi with a whisk.

Marinate the tuna steaks for at least 10 minutes but up to a day ahead of time.

Set your grill up for direct, high heat

Take tuna steaks out of marinade and roll in the sesame seeds.

Put tuna over hot coals for 1 to 2 minutes depending on desired doneness. The tuna in the picture was cooked for 1 minute on each side.