1. In a bowl, mix ground beef, breadcrumbs, egg, Worcestershire sauce, mustard, garlic powder, onion powder, salt, and pepper.

2. Shape mixture into 5–6 oval patties.

3. Heat olive oil in a skillet over medium-high heat.

4. Sear patties for 2–3 minutes per side until browned; remove and set aside.

5. In the same skillet, add mushrooms and onions; sauté until softened and golden.

6. Whisk in beef broth and ketchup, scraping up brown bits from the pan.

7. Return patties to the skillet, reduce heat to low, cover, and simmer for 15–20 minutes.

8. Stir in cornstarch slurry to thicken the gravy.

9. Simmer uncovered for 3–5 more minutes until the sauce is rich and glossy.

10. Serve hot with mashed potatoes or egg noodles, topped with mushroom gravy and parsley.