Salisbury Steak with Mushroom Gravy

Combine ground beef, finely chopped onion, beaten eggs, 1 tablespoon of savory Worcestershire sauce, fragrant parsley, 2 teaspoons of salt, a pinch of garlic powder, and a dash of onion powder in a bowl. Divide the mixture into 6 equal parts and shape each portion into a patty.

Preheat a large skillet over medium-high heat and cook 3 patties at a time until they develop a slight brown hue on one side, approximately 5 minutes. Flip the patties and continue cooking until they are browned on both sides, taking about 5 minutes more. Repeat the process with the remaining patties, carefully draining off any excess moisture that accumulates during cooking. Transfer the cooked patties to a serving plate and cover them with aluminum foil to maintain their warmth, or bake them in the oven to keep them warm.

Melt 2 tablespoons of butter in the same skillet over medium heat and sauté sliced mushrooms until they turn golden brown, about 5 minutes. Transfer the cooked mushrooms to a separate bowl, reserving the butter in the skillet.

Gradually stir 1-2 tablespoons of all-purpose flour into the melted butter until it dissolves. Slowly pour in 1 cup of beef broth, stirring continuously until the mixture thickens, approximately 7 minutes. Add another 1 teaspoon of Worcestershire sauce; cook, stirring frequently, until the gravy starts to thicken slightly, about 5 minutes. Stir in 1 tablespoon of sour cream and season with salt and pepper to taste. Cook, stirring constantly, until the sour cream is fully incorporated and the gravy has a light brown hue, about 2 minutes.

Stir the cooked mushrooms back into the gravy. Remove from heat and let it cool until thickened, about 2 minutes. Serve the warm gravy over the cooked steak patties.