Mix red pepper powder, sugar, soy sauce, minced garlic, corn syrup, salt, gochujang, and black pepper to create the seasoning sauce. Let it rest to enhance flavors.

While the sauce is resting, chop the vegetables (onion, cabbage, carrot, green onion, perilla leaves) and slice the sundae.

Heat oil in a pan and stir-fry cabbage and carrot first as they take longer to cook.

Add onion and sundae to the pan and continue stir-frying until partially cooked.

Pour the prepared seasoning sauce into the pan and mix well. Adjust the heat to prevent the sauce from burning.

Add green chilies, green onion, and perilla leaves. Stir-fry quickly over high heat to finish cooking.