- In a bowl, mix ground beef, breadcrumbs, egg, Worcestershire sauce, garlic powder, onion powder, salt, pepper, ketchup, and Dijon mustard. 
- Divide the mixture into 4 equal portions and shape into oval patties. 
- Heat olive oil in a large skillet over medium heat. Cook the patties for 4–5 minutes per side until browned. Remove and set aside. 
- In the same skillet, melt butter. Add sliced onions and mushrooms, and cook for 5 minutes until softened. 
- Stir in beef broth, Worcestershire sauce, ketchup, Dijon mustard, salt, and pepper. Bring to a simmer. 
- Add cornstarch mixed with water and cook until the gravy thickens. 
- Return the patties to the skillet and simmer for 5–7 minutes, spooning gravy over them until fully cooked. 
- Serve hot with mashed potatoes, rice, or egg noodles, and drizzle extra gravy over the top.