01 -
Preheat oven to 175°C and lightly grease a 23×33 cm baking dish.
02 -
Combine ground beef, breadcrumbs, egg, garlic powder, onion powder, salt, and black pepper in a large bowl. Mix gently until just combined, then shape into 4 to 6 oval patties.
03 -
Heat a skillet over medium heat. Sear each patty for 2 to 3 minutes per side until browned but still undercooked inside. Transfer patties to the prepared baking dish.
04 -
Whisk together cream of mushroom soup, milk, and Worcestershire sauce in a bowl until fully blended. Pour the sauce evenly over the hamburger steaks.
05 -
Evenly distribute sliced onions and mushrooms over the steaks and sauce.
06 -
Cover the baking dish with aluminum foil and bake for 30 to 35 minutes. Remove foil and bake an additional 10 minutes, until the sauce is bubbling and the steaks are fully cooked.
07 -
Garnish with chopped fresh parsley before serving. Pair with mashed potatoes or egg noodles if desired.