Remove moisture from the tofu using a kitchen towel.
Drain the oil from the tuna and set it aside.
Put the chopped tofu and tuna in a bowl and mix well.
Add chopped green onion, garlic, gochujang (Korean chili paste), doenjang (soybean paste), chili powder, sesame oil, and sesame seeds, then mix again.
Cook the mixture in a pan over medium heat, stirring until the moisture evaporates.
Serve the finished ssamjang on lettuce, cabbage, perilla leaves, or other leafy vegetables.