Mince red onion and garlic. Try to cut them into similar pieces.
Add oil and fry garlic and red onion until slightly soft and aromatic. Then add the beef stock. If you don’t have beef stock, replace it with water.
Add ground black peppercorn, oyster sauce, light and dark soy sauce, sugar, and salt.
Mix cornstarch with water. Stir well. Then, slow down the fire and pour the starch water in.
Simmer for another minute until the sauce is thickened and the aromatics and seasoning flavors combine well.
