Thinly slice the cucumber, lightly salt it, then remove excess moisture.
Pat the tofu dry with a paper towel and cut it into bite-sized pieces.
Drain oil or water from the canned tuna and prepare it.
In a bowl, mix tofu, cucumber, and tuna with seasoning sauce (soy sauce, sesame oil, minced garlic, chili flakes, sesame seeds, etc.).
Transfer to a plate and finish by sprinkling sesame seeds and chopped scallions.