Add the chunked beef stew meat, beef broth, finely diced onions, brown gravy mixes, Worcestershire sauce, garlic powder, onion powder, and black pepper into your slow cooker.
2 pounds beef stew meat, 2 cups beef broth or beef stock, 1 yellow or sweet onion, 2 packages (1 oz each) brown gravy mix, 1 tablespoon Worcestershire sauce, 5 garlic cloves, 1 teaspoon onion powder, 1 teaspoon garlic powder, ½ teaspoon black pepper