In a mixing bowl, combine ground beef, bread crumbs, egg, Worcestershire sauce, garlic powder, onion powder, salt, and pepper. Mix until just combined.

Form the mixture into 4 oval patties.

Heat olive oil in a skillet over medium heat. Add the patties and cook for about 4-5 minutes on each side until browned and cooked through. Remove from skillet and set aside.

In the same skillet, add onions and mushrooms. Sauté until softened, about 5 minutes.

Sprinkle flour over the mushrooms and onions, stirring to combine. Cook for 1 minute.

Gradually add beef broth and soy sauce, stirring constantly until the gravy thickens, about 3-5 minutes.

Return the patties to the skillet, spooning gravy over them. Simmer for an additional 5 minutes.

Serve hot with mashed potatoes or rice, garnished with parsley if desired.