In a blender, puree until smooth the garlic, ginger, soy sauce, and lime juice. Remove to a bowl and mix in the cilantro. Slice the tuna into thin, 1-inch long pieces.
Place tuna on a serving platter and spoon soy sauce mixture over each slice. Dot each piece with each of the purees, aji amarillo, and rocoto pepper.
Recipe courtesy Aaron Sanchez