Mix the sugar, red pepper, gochujang, soju, soy sauce, scallions, garlic, minced ginger and diced onion into a marinade paste.
Place the pork in a suitably sized container and coat it thoroughly with the marinade. Cover with cling-film and let sit for 30 minutes.
Heat up an oiled wok until it starts smoking a bit. Add in the meat and all its marinade. Fry, stirring constantly, until caramelized.
Add in the mushrooms, bell pepper, sugar snaps or snow peas, ginger match sticks chilies.
Lightly sprinkle toasted sesame seeds over each serving.
Serve with boiled rice and a little spicy, fermented cabbage kimchi on the side.