Cut the beef and squid into bite-sized pieces.
Julienne the onion, green onion, and garlic.
Add sesame oil to a pan and sauté the garlic to bring out its aroma.
Add the beef and squid and stir-fry over high heat.
Add the onion and green onion, and continue stir-frying.
Season with soy sauce, gochujang (Korean chili paste), and pepper.
Once all the ingredients are cooked, finish with a splash of sesame oil.