Prepare the Beef: Cut the beef into strips and make a marinade with black pepper, corn starch, water, oyster sauce, light soy sauce, shaoxing wine, and red wine. Stir, then add the beef and mix thoroughly.
Prepare the Vegetables: Mince garlic and slice bell peppers and red onion.
Make the Sauce: Combine cornstarch, water, sugar, light soy sauce, dark soy sauce, red wine, salt, oyster sauce, and shaoxing wine.
Cook the Beef: Set the stove to high heat and add oil to the wok. Add oil to the beef and mix it around. Cook the beef for about a minute, then transfer it to a plate when it slightly changes color.
Cook the Vegetables: Cook the minced garlic for 20 to 30 seconds. Add the veggies and cook for roughly 90 seconds.
Combine and Finish: Add the beef back in, cook for a minute, then pour the sauce and cook for another minute. Season with sesame oil and black pepper, give it a stir and cook for a minute. Plate the dish.