In a small bowl, combine garlic powder, onion powder, salt and pepper. Stir. Toss stew meat in spice mixture to season. Place in slow cooker.
In a bowl, combine soy sauce, hoisin sauce, chili paste, ginger and oil. Whisk to combine. Pour over beef in slow cooker.
Cook on low for 6-8 hours. Add bell pepper and onion to slow cooker 30 minutes before ready to serve.