Cut the beef into bite-sized pieces.
Finely chop the onion and green onion.
Add perilla oil to a pan and stir-fry the beef.
Once the beef is cooked, add the onion and green onion and stir-fry.
Cut the tofu into suitable pieces and add to the pan.
Season with soy sauce, minced garlic, salt, and pepper.
Stir-fry until all ingredients are cooked.
Transfer to a bowl and drizzle sesame oil on top.