Boil buckwheat noodles in boiling water and rinse under cold water.
Season bulgogi beef slices with soy sauce, sugar, minced garlic, etc., then stir-fry in a pan.
Mix mayonnaise, gochujang (Korean chili paste), and perilla oil well to make the sauce.
Top the cooked buckwheat noodles with stir-fried bulgogi and the prepared sauce.
Sprinkle with seaweed flakes, chopped scallions, sesame seeds, etc., and mix well before eating.