Step 1: Make the Hamburger Steaks

1. Mix the Ingredients: In a large mixing bowl, combine the ground beef, breadcrumbs, egg, Worcestershire sauce, garlic powder, onion powder, salt, and black pepper. Use your hands to gently mix until just combined; do not overwork the meat.
2. Form the Patties: Divide the mixture into 4 equal portions and shape each portion into a patty about 1/2 inch thick. Use your thumb to make a small indentation in the center of each patty to prevent them from puffing up during cooking.

Step 2: Cook the Hamburger Steaks

1. Sear the Patties: Heat a large skillet over medium-high heat and add a drizzle of oil or a pat of butter. Sear the hamburger steaks for 3-4 minutes per side, or until they develop a golden-brown crust. They don’t need to be fully cooked at this stage, as they’ll finish cooking in the gravy.
2. Remove and Set Aside: Transfer the seared patties to a plate and set aside while you make the gravy.

Step 3: Make the Gravy

1. Sauté the Onions and Mushrooms: In the same skillet, melt the butter over medium heat. Add the sliced onions and cook for 5 minutes, or until softened and lightly caramelized. If using mushrooms, add them now and cook for an additional 3 minutes.
2. Add the Flour: Sprinkle the flour over the onions and mushrooms, stirring to coat them evenly. Cook for 1-2 minutes to remove the raw flour taste.
3. Deglaze the Pan: Slowly pour in the beef broth while stirring to combine. Scrape up any browned bits from the bottom of the pan for extra flavor.
4. Season the Gravy: Stir in the Worcestershire sauce, soy sauce (if using), garlic powder, and thyme. Bring the gravy to a gentle simmer and cook until slightly thickened, about 3-4 minutes.

Step 4: Combine and Simmer

1. Return the Patties to the Skillet: Nestle the hamburger steaks back into the skillet, spooning some of the gravy over the top.
2. Simmer: Reduce the heat to low, cover, and simmer for 10-12 minutes, or until the patties are fully cooked (internal temperature of 160°F/71°C). Stir the gravy occasionally to prevent sticking.
3. Taste and Adjust: Taste the gravy and adjust the seasoning with additional salt and pepper if needed.

Step 5: Serve

1. Plate and Garnish: Serve the hamburger steaks with a generous spoonful of gravy, and garnish with chopped parsley if desired. Pair with mashed potatoes, rice, or your favorite side dishes for a complete meal.