In a mixing bowl, combine the ground beef with breadcrumbs, egg, ketchup, Worcestershire sauce, garlic powder, onion powder, and a pinch each of salt and pepper. Blend gently until the mixture is just incorporated, then shape into 4 to 6 oblong patties.
Warm 1 tablespoon of olive oil in a broad skillet over medium-high heat. Add the beef patties and cook for about 3 to 4 minutes per side, or until a deep brown crust forms. Transfer the patties to a plate and set aside.
Using the same pan, melt the butter with the remaining tablespoon of olive oil over medium heat. Stir in the mushrooms and diced onion, and sauté for 5 to 7 minutes, until softened and beginning to brown.
Dust the mushroom-onion mixture with the flour, stirring continuously to form a roux. Let it cook for about 1 minute to eliminate the raw flour taste.
Gradually pour in the beef broth while whisking, ensuring a smooth consistency. Add Worcestershire sauce, garlic powder, and season with salt and pepper. Let the mixture come to a gentle simmer, cooking for 2 to 3 minutes until the gravy starts to thicken.
Return the browned patties to the skillet, nestling them into the bubbling gravy. Cover with a lid and reduce the heat to low. Let the dish simmer for 10 to 15 minutes, or until the patties are fully cooked through and the sauce has developed a rich consistency.
If using, sprinkle with fresh parsley just before serving. These steaks are best enjoyed hot alongside mashed potatoes, buttered egg noodles, or steamed rice.