Cut the king oyster mushrooms and squid into bite-sized pieces.
Slice the onion and green onion as well.
Add cooking oil to a pan and stir-fry the green onion to bring out its flavor.
Add the squid first and stir-fry.
Add the king oyster mushrooms and onion and stir-fry together.
Add the seasonings: soy sauce, gochujang, minced garlic, and red pepper powder, then stir-fry.
Once all ingredients are cooked, turn off the heat and plate it.