Cut the tofu into bite-sized pieces.
Drain the oil from the tuna using a strainer.
In a bowl, mix the tuna, chopped onion, chopped green onion, doenjang (soybean paste), gochujang (red chili paste), minced garlic, sesame oil, and sesame seeds to make the ssamjang sauce.
Place the ssamjang sauce on top of the tofu to finish.