Salisbury Steak with Mushroom Onion Gravy

Ingredients

• 1 1/2 lb ground beef (85/15)
• 1/3 cup panko breadcrumbs
• 1/4 cup whole milk
• 1 large egg
• 1 tablespoon Worcestershire sauce
• 2 teaspoons Dijon mustard
• 1 1/2 teaspoons kosher salt
• 3/4 teaspoon black pepper
• 2 tablespoons vegetable oil
• 1 large yellow onion, halved and thinly sliced
• 8 oz white mushrooms, sliced
• 3 tablespoons unsalted butter
• 3 tablespoons all-purpose flour
• 3 cups beef broth
• 1 tablespoon ketchup
• 1 teaspoon Worcestershire sauce, for the gravy

Before you cook

• Stir the panko and milk together in a large bowl and let them soak for 5 minutes.
• Halve and thinly slice the onion.
• Slice the mushrooms.

Steps

1. Whisk the egg, Worcestershire sauce, Dijon, salt and pepper into the soaked panko.
2. Add the ground beef and mix until just combined, then shape it into four oval patties about three quarters of an inch thick.
3. Heat the oil in a large skillet over medium-high heat until it shimmers.
4. Sear the patties for 4 minutes per side, until a dark crust forms, then move them to a plate.
5. Lower the heat to medium, add the butter, onion and mushrooms to the skillet, and cook for 10 minutes until the onions are golden and the pan is dry.
6. Sprinkle the flour over the vegetables and stir for 1 minute.
7. Pour in the beef broth while whisking, scraping the browned bits off the bottom of the pan.
8. Stir in the ketchup and the extra teaspoon of Worcestershire sauce and bring the gravy to a simmer.
9. Return the patties and any juices to the skillet, cover, and simmer over low heat for 12 minutes.
10. Taste the gravy for salt and serve the patties smothered in it.