Drain the oil from the tuna using a sieve.
Finely chop the onion.
Finely chop the Cheongyang chili pepper and green onion as well.
In a bowl, mix together the tuna, doenjang (soybean paste), gochujang (red chili paste), minced onion, Cheongyang chili pepper, green onion, and minced garlic.
Add sesame oil and roasted sesame seeds to taste and mix well.
Enjoy the tuna ssamjang wrapped in lettuce, perilla leaves, or other wrap vegetables.