Salisbury Steak in Mushroom Gravy

2 pounds lean ground beef
2 large eggs, lightly beaten
1/4 cup unseasoned dry breadcrumbs
2 teaspoons plus 1 tablespoon Worcestershire sauce
2 teaspoons kosher salt
1/2 teaspoon ground mustard
1/4 teaspoon freshly ground black pepper
5 tablespoons unsalted butter
8 ounces cremini mushrooms, cleaned, stems trimmed, and quartered (about 2 1/2 cups)
2 medium shallots, minced
4 tablespoons all-purpose flour
1/2 cup dry red wine
1 (14-ounce) can low-sodium beef broth

Heat oven to 350°F and arrange rack in middle.

Combine ground beef, eggs, breadcrumbs, 2 teaspoons of the Worcestershire sauce, salt, mustard, and pepper in a large bowl and mix to combine.

Shape into 8 (3-1/2-by-2-1/2-by-1-inch) oval patties and set aside.

Heat a large frying pan over medium heat and melt 1 tablespoon of the butter. Once butter foams, add 4 patties and brown, about 3 to 4 minutes per side.

Transfer patties to a 13-by-9-inch baking dish.

Brown remaining 4 patties, and transfer to the baking dish. Drain all fat from the pan but leave any browned bits.

Return the pan to medium heat and melt remaining 4 tablespoons butter.

Add mushrooms and shallots and season with salt and freshly ground black pepper.

Cook, stirring rarely, until mushrooms are slightly browned and soft, about 4 minutes.

Sprinkle flour over mixture and stir until fully incorporated.

Cook, stirring occasionally, until flour is lightly toasted, about 3 minutes. Add red wine and stir, scraping up any browned bits from the bottom of the pan.

Slowly pour in broth and stir until smooth. Let mixture come to a boil and cook until sauce is reduced by half, about 13 minutes.

Add remaining 1 tablespoon Worcestershire sauce.

Taste and add salt and freshly ground black pepper as needed.

Pour sauce over patties in the baking dish and cover with aluminum foil.

Bake for 20 minutes or until meat is tender and slightly pink in the middle.