Combine Soy sauce, water, vinegar, Vegetable oil, garlic, and pepper. Pour over meat and marinate. Refrigerate 4 to 6 hours, turning occasionally.

Sauté onions and pepper in butter until tender. Season with lemon pepper. Keep hot while cooking meat.

Remove meat from marinade and place on grill or broiler pan. Cook to desired doneness. Cut meat across grain into ½ inch strips heap with onion and peppers.

Serve with warmed tortillas for wrapping. Top with salsa and guacamole.