Cut the beef in thin bite-sized stripes. Transfer it to a bowl and add gochujang, light soy sauce, sugar, pepper and sesame seed oil. Mix well and set aside.
Slice green onions diagonally into long stripes. Chop the white onion, finely mince the garlic and ginger.
Toast some sesame seeds in a dry pan until golden. Set them aside.
Heat the vegetable oil in a large pan and add the beef. Cook for a few minutes until the beef is done. Then add the green onion, white onion, garlic, ginger and edamame beans. Cook until the onions become soft. Taste and adjust the seasoning if needed.
Plate and sprinkle with the toasted sesame seeds. Serve with rice.
Notes
You can adjust how spicy you want your beef to be by adding more or less gochujang. Also, have in mind that gochujang is salty, so you might need to adjust the amount of soy sauce you add.