Clean and prepare the shrimp and squid thoroughly.
Slice the vegetables (onion, bell pepper, Korean chili pepper) and set aside.
Heat olive oil in a pan and stir-fry the shrimp and squid.
Add the vegetables and stir-fry together over high heat.
Season with soy sauce, gochujang (Korean chili paste), and sugar.
Finish by drizzling sesame oil and sprinkling sesame seeds.