Prepare the Ahi Tuna: Begin by rinsing the ahi tuna under cold water and patting it dry with paper towels. Then, using a sharp knife, carefully cut the tuna into bite-sized cubes and place them in a mixing bowl.
Prepare the Marinade: In a separate bowl, combine the soy sauce, sesame oil, and any optional ingredients such as chopped green onions, sesame seeds, or chili pepper. Mix the marinade ingredients well to ensure they are evenly distributed.
Marinate the Tuna: Pour the marinade over the cubed tuna in the mixing bowl, ensuring that all the pieces are coated evenly. Gently toss the tuna to combine it with the marinade. Cover the bowl with plastic wrap and refrigerate for about 15-30 minutes to allow the flavors to meld together.
Optional Additions: While the tuna is marinating, you can prepare any optional additions such as diced avocado, cucumber, tobiko (fish roe), or rehydrated and chopped seaweed (such as Wakame).
Assemble and Serve: Once the tuna has marinated to your liking, remove it from the refrigerator. Add any optional ingredients you prepared earlier and gently toss to combine. Transfer the ahi poke to a serving dish or bowl.