In a medium saucepan, melt the butter over medium heat. Add the flour, whisking constantly, and cook for 1-2 minutes until golden brown. Slowly pour in the beef broth, whisking to prevent lumps. Add Worcestershire sauce, onion powder, garlic powder, salt, and black pepper. Stir well. Bring to a simmer and cook for 5-7 minutes, or until the gravy thickens. Remove from heat.