For the Salisbury steak…
- In a mixing bowl, combine the ground beef, diced onion, panko bread crumbs, beaten egg, Worcestershire sauce, minced parsley, shallot and roasted garlic, cracked pepper, and kosher salt. Mix until well combined.
 - Shape the mixture into 3-4 oval-shaped patties.
 - Melt 1 tablespoon of butter in a large skillet over medium heat. Sauté the patties for 4-5 minutes per side, or until nicely browned. Remove the patties from the pan and set aside.
 
For the mushroom gravy…
- In the same skillet, add 1 tablespoon of butter, sliced mushrooms, and thinly sliced shallots. Sauté for 4-5 minutes.
 - Add the fresh thyme and cook for an additional minute.
 - Dust the mixture with flour and cook for 1-2 minutes until thickened.
 - Gradually stir in the beef broth, 1/2 cup at a time, allowing the mixture to come to a boil in between each addition. Add more broth until desired thickness is achieved. Season with salt and pepper.
 - Return the steak patties to the gravy, reduce the heat to low, and allow to braise until the patties are cooked through.
 - Serve the Salisbury steaks over mashed potatoes, topped with fresh parsley for garnish.