Ingredients
Beef Patties
1.5 lbs ground beef: (80/20 preferred for moisture)
1/2 cup breadcrumbs or panko
1 large egg
1 tbsp Worcestershire sauce
1 tsp onion powder & 1 tsp garlic powder
1/2 packet dry onion soup mix (or 1 tsp beef bouillon powder)
1 medium yellow onion: Diced (placed at the bottom of the dish)
Salt & black pepper: To taste
Mushroom Gravy
8 oz cremini or white mushrooms: Sliced
2 tbsp butter
3 tbsp all-purpose flour
2 cups beef broth
1 tbsp Worcestershire sauce
1 tsp Dijon mustard
Preparation
1. Prep the Base: Preheat your oven to 375°F (190°C). Spread the diced yellow onions evenly across the bottom of a 9×13-inch baking dish.
2. Form Patties: In a large bowl, combine ground beef, breadcrumbs, egg, Worcestershire sauce, onion powder, garlic powder, salt, and pepper. Mix until just combined and shape into 5 or 6 oval patties.
3. Assemble for Baking: Arrange the patties on top of the bed of diced onions in the casserole dish. Sprinkle extra breadcrumbs or dry soup mix over the top if desired.
4. Make the Gravy: Melt butter in a skillet over medium heat. Add sliced mushrooms and sauté for 5 minutes until browned. Whisk in the flour and cook for 1 minute. Slowly pour in beef broth, Worcestershire sauce, and Dijon mustard, whisking continuously until the gravy thickens.
5. Bake: Pour the hot mushroom gravy directly over the raw patties and onions in the casserole dish. Cover tightly with aluminum foil and bake for 35 to 40 minutes until the patties are cooked through (internal temp of 160°F/71°C).
6. Serve hot spooned generously over buttery mashed potatoes.