In the glass baking dish, pour in the water, soy sauce, lime juice, rice wine vinegar, 1 tablespoon sesame oil, sriracha sauce, and mirin. Whisk the marinade together with the whisk until everything is well combined. Place the ahi steak into the marinade and place the glass baking dish with the ahi steak in the refrigerator for 30 minutes. After 30 minutes, flip the ahi steak over so that the ahi has the chance to fully marinate on all sides, and allow to marinate for 30 more minutes.
After the tuna steak has finished marinating, drain off the marinade and pat the steak dry with paper towels on all sides. Pour Sweet Heat Rub onto the plate and rub the remaining tablespoon of sesame oil generously on all sides of the tuna steak, and then gently place the tuna steak into the seasoning on the plate, turning on all sides to coat evenly.
Grill 400 degrees cook tuna steak 2.5 mins each side
