About the Recipe
I had a conversation with my friends about jaeyuk because I always associate this dish with pork.
Technically, that does not have to be the case and I concede my defeat, but I will say that you should always make this dish with pork as this is how I have always had it. (Bulgogi is the beef version… not really as the meat is interchangeable for both dishes but indulge me…)

Ingredients
800g-1.2kg of pork (anything with a reasonable amount of fat is fine including but not limited to belly and shoulder - I recommend you stick to these two as they are not very difficult to find)
1-2 onions depending on size, thinly sliced
2-3 spring onions depending on size, sliced
Couple of tablespoons of both light and dark soy
1 tablespoon of mirin (if you do not have any substitute with 1 teaspon of honey)
Gochugaro (Korean chilli flakes - there isn't really any good substitute for this but you might be able to get away with using some chilli flakes)
1 teaspoon sesame oil
Pinch of sesame seeds for decoration
3 cloves finely chopped/minced/grated garlic
Preparation
Prep the pork: freeze the pork for around 1h. Even if you bought thin strips of pork belly these are usually a couple of centimeters thick and you want to cut those thinner. Regardless of what pork you bought, freeze for around an hour to make it easier to slice. Slice as thin as you can, the thickness does not really matter too much as long as its thin enough.
Prepare the marinade: mix all the rest of your ingredients except the sesame seeds and spring onion then cover the pork with the marinade. You can cook it immediately although it will benefit from marinading overnight.
Cook: add some oil and the whites of the spring onions first to the pan then add your meat and cook until done.
Serve with some freshly cooked rice, sesame seeds and spring onion sprinkled over the top.