1. Mix red pepper powder, soy sauce, Omija Cheong, and half of the garlic with the sliced beef.
2. Heat olive oil in a pan, add the rest of the garlic, and make garlic oil.
3. Add the beef, season with salt and pepper, and stir-fry.
4. Add onions, green onions, and mushrooms, then drizzle with sesame oil and serve.
