Take off a few layers of cabbage. Rinse it under running water so it can get some moisture on the leaves. Then place all of the leaves in a microwave friendly bowl. Pour in ½ cup of water into the bowl. Cover with plastic wrap. Poke a few holes so it can steam. Microwave for 7-8 minutes. (Or alternatively, steam the leaves for 5-6 minutes)
Cut spring onion into small slices. Dice mushroom and onion into small bite-sized cubes.
Put frying pan on medium-low heat. Open up the tuna can. Squeeze out the oil into the frying pan. Once the oil is hot, place in the spring onions. Once the spring onions start to sizzle, place in the diced onions and mushrooms.
Stir it around until the onions start to turn slightly translucent. Then place in doenjang (1T), gochujang (1T), gochugaru (1T), minced garlic (1T). Mix it into the veggies.
Then add in water (1 cup) into the mixture. Stir it around. Wait until it comes up to boil again.
Once it starts to boil, add-in the honey (1T) and the tuna. Mix it in.
Put it on low heat. Let it simmer and reduce for about 5 minutes.
After 5 minutes, there will still be some liquid - that's ok. Turn off heat and place in sesame oil (1T).
Place ssamjang into a serving bowl and garnish with sesame seeds (1T)
To eat: Add rice onto a piece of steamed cabbage or lettuce. Then add some of the tuna ssamjang on top. Or alternatively, roll and cut it like sushi if you like (reference video).