Cut the beef into bite-sized pieces.
Slice the onion and green onion thinly.
Heat sesame oil in a pan and stir-fry the beef.
When the beef is halfway cooked, add the onion and green onion and stir-fry.
Add gochujang, soy sauce, and minced garlic, and stir-fry evenly.
Once the flavors are absorbed, turn off the heat and transfer to a plate.