In China, there are two main branches of Jajangmyun. The southern Jajjangmyun which is common in Hong Kong consists of stripes of pork cooked in an orange sauce which is slightly spicy spreaded on top of egg noodle (thin, chewy, yellowish that is used for Wonton noodle soup). In the north, it's wheat noodle covered by black bean sauce. Usually, you see northern jajangmyun eaters having cucumber in one hand and chopstick in the other.
In Korea, you eat jajangmyun at Chinese restaurant. It's a variation from the Northern jajangmyun by immigrants and Chosun people (i.e.Koreans living in Northeast China, just North of the North Korea border). Jajangmyun is such a simple and yet fulfilling dish that it became one of the most popular dishes in Korea. When you see a delivery man carrying a rectangular metal box, chances are you will find jajangmyun, jjamppong and mandoo in plastic bowl with an industrial strength clingwrap mounted on top to avoid spilling.
The Korean jajangmyun is a tad sweeter than it's Chinese cousin. I like all kinds of Jajangmyun and over the years, I developed my version which I think is better than the ones you get at restaurants in Seoul. The big difference is I don't use potato or the water that cooked the noodle to thicken the sauce. I use sesame oil to keep the sauce not as thick and to add fragrance.
Generous amount of onion cut into small pieces.
Two to three gloves of garlic, minced
Zucchini, carrot, and a small quantity of potato - all diced
Diced pork should be marinated with light soy, dark soy, a little bit of sugar, sesame oil, white pepper and starch for at least 30 minutes before cooking
When the wok is red hot, add oil and onion. Stir fry the onion till it's soft and starting the caramerlize. Do not be cheap on time and cheat. It has to start caramelize! Add pork and stir fry till the sides are brown. Add the other vegetables and two tablespoons of jajang. Add some water and mix the sauce well. Cover the wok and let the sauce simmer. When done, add a generous dash of sesame oil (pure sesame oil, never use blended ones)
For the noodle, I like using sootamyun (hand made noodle). Take the noodle out of the boiling water when it's a little undercook. Rinse the noodle in another pot of hot water. The purpose is to wash out the extra starch.
Put the noodle in a bowl. Here's another thing. Don't just dump the noodle in as that will make mixing with the sauce difficult. Organize the noodle neatly. Add sauce on top and eat with raw onion and uncooked jajang sauce and yellow picked radish.
That's what I call a good dinner!