Wash the king oyster mushrooms and cut them into bite-sized pieces.
Thinly slice the onion and green onion.
Heat cooking oil in a pan and grill the mushrooms over high heat.
Season the mushrooms with salt and pepper.
Once the mushrooms are golden brown, place them on a plate.
Mix with onion, green onion, gochujang (Korean chili paste), sesame oil, sesame seeds, and minced garlic.