Steps:

• In a wok or skillet, stir-fry green peppers and onion in 1 tablespoon oil for 2-3 minutes. Add mushrooms; stir-fry 1 minute longer. Remove and keep warm., Season the beef with salt and pepper. In the same skillet, stir-fry the beef and garlic in remaining oil for 6-8 minutes or until no longer pink; drain., Combine the cornstarch, apple juice and water until smooth; stir into the beef mixture. Bring to a boil; cook and stir for 1 minute or until thickened. Return the vegetables to the pan; heat through. Serve over the rice.

Steps:

• Slice beef into thin slices with the grain. Cut each strip across the grain about 1" long so you have small thin slices. Place in a bowl and add 4 tsp of soy sauce, 1 tbsp of rice wine, 1 tsp cornstarch and black pepper.
• In a small bowl, mix 3 tbsp soy sauce, 1 tbsp water and 2 tsp cornstarch. Set aside.
• Heat the wok on high heat. Swirl in 2 teaspoons of the oil and add the beef spreading evenly in the wok. Cook undisturbed for 20 seconds letting the beef brown. Using a spatula, stir meat, cooking another 2 minutes. Transfer to a plate.
• Add remaining teaspoon of oil to wok, add peppers and onions and cook about 4 to 5 minutes. Return beef to the wok, add the sauce and red pepper flakes and stir fry about 30 seconds until slightly thickened.