Prepare the Hamburger Steaks

In a large mixing bowl, combine the ground beef, egg, breadcrumbs, Worcestershire sauce, onion powder, garlic powder, salt, and pepper. Mix until just combined; avoid overmixing to keep the patties tender. Divide and shape the mixture into 4 even patties.

Cook the Patties

Heat a large skillet over medium heat with a little oil or butter. Cook the hamburger steaks for 3-4 minutes on each side until browned, then transfer them to a plate and set aside. (They will finish cooking in the gravy.)

Make the Gravy

In the same skillet, add the sliced onions and mushrooms (if using). Sauté for 5-6 minutes until soft and caramelized. Add the minced garlic and cook for another minute until fragrant.

Thicken the Gravy

Sprinkle the flour over the onions and mushrooms and stir to coat. Cook for 1-2 minutes, then slowly pour in the beef broth while stirring to avoid lumps. Add the Worcestershire sauce and season with salt and pepper to taste.

Simmer and Serve

Return the hamburger steaks to the skillet, nestling them into the gravy. Reduce heat to low, cover, and simmer for 10-12 minutes, until the patties are cooked through and the gravy has thickened.

Garnish and Serve

Serve the hamburger steaks with gravy over mashed potatoes, rice, or noodles. Garnish with freshly chopped parsley.