This is spicy (for me)... right at the upper end of what I find wonderful. But the original (at https://www.maangchi.com/recipe/buldak)... YIKES! I never tried it with the 1/2 c of Korean hot pepper flakes, discretion being the better part of pain management, but immediately dropped it to 1 T. I kept the full amount of gochujang because, well, gochujang has extra tastiness that goes along with its impressive kick!
1.5 lbs chicken thighs, cut into 3/4-1" cubes
1 T Korean hot pepper flakes
2 T gochujang (Korean chili paste)
1 T soy sauce
2.5 T vegetable oil - DIVIDED
1/4 t black pepper (a staple of Korean dishes... but in this one I doubt it impacts the flavor AT ALL)
3 T brown sugar (down from the original 1/3 c... feel free to increase it if you like)
5 garlic cloves, minced
2 t minced ginger
1/4 c water
mozzarella cheese - somewhere between 5 oz (what seemed sane for a weeknight) and 12 oz (what the original called for), chunked or shredded
1-2 green onions, chopped
Combine hot pepper flakes, gochujang, soy sauce, 1.5 T tablespoons vegetable oil, ground black pepper, brown sugar, garlic, and ginger in a bowl. Mix it well into a sweet and spicy paste. Add the chicken and mix well by hand. You can let it rest in the fridge until you're ready to cook or start right in.
Heat a 10" cast iron (or other broiler-safe skillet) over medium-high heat. Add remaining 1 T oil and the chicken. Use the water to rinse the bowl and get the last of the sauce into the pan. Cover and cook over medium high heat for 10 minutes. (Recipe notes if you use a regular non-stick skillet, it will take 7 to 8 minutes and you will not broil at the end.) Be sure not to burn the chicken.
Uncover, stir and turn over the chicken with a wooden spoon. Turn down the heat very low. Cover and let cook another 10 minutes, until the chicken is fully cooked. If you’re using cheese, pre-heat the oven broiler.
When the chicken is cooked, put the cheese over the top. Slip it into the oven for a few minutes until the cheese is melted and bubbly. Top with green onion.
I served this over cheesy orzo (was also considering cheesy polenta, but didn't have any milk on hand) and it was delicious, a good partner to the spice. See the original recipe for a far more traditional added-carb option.