In a bowl, marinate the beef slices with soy sauce, Worcestershire sauce, black pepper, and sesame oil for 3-4 hours.
Heat up oil in a wok or pan. Brown the marinated beef then add garlic, onions, and ginger to sauté for 2-3 minutes.
Stir in broccoli florets and carrots. Cover the wok to soften the vegetables.
Stir in the sweet peppers, hoisin sauce, and water. Cover to continue cooking and soften the vegetables.
Stir in the snow peas.
Then the water and cornstarch mixture to thicken the sauce.
Beef & Vegetable Stir-Fry