In a large bowl, combine the ground beef, breadcrumbs, milk, finely chopped onion, egg, Worcestershire sauce, garlic powder, onion powder, salt, and pepper. Mix until well combined. Shape the mixture into 4-6 patties.
Heat the olive oil in a large skillet over medium-high heat. Add the patties and cook for 3-4 minutes on each side, until browned. Remove the patties from the skillet and set aside.
In the same skillet, add the butter and sliced onions. Cook for about 5 minutes until the onions are softened. Add the sliced mushrooms and cook for an additional 3-4 minutes.
Sprinkle the flour over the onions and mushrooms, stirring to combine. Cook for 1-2 minutes until the flour is lightly browned.
Gradually stir in the beef broth and Worcestershire sauce, scraping up any browned bits from the bottom of the skillet. Bring the mixture to a simmer and cook for 5-7 minutes until the gravy thickens.
Return the patties to the skillet, spooning some of the gravy over the top. Reduce the heat to low and simmer for 10-15 minutes, until the patties are cooked through and the flavors meld.
Serve the Salisbury steaks hot, topped with the onion and mushroom gravy. Garnish with freshly chopped parsley. Pair with mashed potatoes, rice, or your favorite vegetables.
Prep Time: 15 minutes | Cooking Time: 30 minutes | Total Time: 45 minutes
Kcal: 400 kcal | Servings: 4 servings
