In a large mixing bowl, combine ground beef, beaten egg, diced onion, garlic powder, bacon, breadcrumbs, salt, and pepper. Mix thoroughly until combined.

Divide the mixture into four equal portions and shape each into a patty, about ¾ inch thick. Dust lightly with flour.

Heat olive oil in a skillet over medium heat. Cook patties for 5-6 minutes each side until golden-brown and internal temperature reaches 160°F.

In the same skillet, add chopped onion and sauté for 2-3 minutes until soft.

Whisk together flour and water in a bowl. Pour this into the skillet, stirring well to prevent lumps. Cook for 2 minutes until slightly thickened.

Stir in the brown gravy mix and Worcestershire sauce. Adjust seasoning with salt and pepper.

Add sliced mushrooms to the gravy, simmer for 5 minutes.

Return patties to the skillet, nestling them into the gravy. Let simmer for an additional 20 minutes.

Once thickened, serve the Hamburger Steak Patties with mushroom gravy over them.