Finely chop the tuna and vegetables.
Add tuna, doenjang (soybean paste), gochujang (Korean chili paste), minced garlic, chopped scallions, Cheongyang chili, toasted sesame seeds, and sesame oil to a bowl and mix well.
Put the mixed ingredients into a pot and stir-fry over medium heat for 2-3 minutes.
Serve the finished tuna ssamjang cold or warm, wrapped in lettuce or perilla leaves.