In a large bowl, combine the ingredients for the steaks and mix well. Once mixed, divide the mixture into 4 equal parts, and shape into oval size patties, about 3/4" thick.

In a large skillet, over medium-high, heat 1 tablespoon of oil. When oil is hot, add the meat patties, and sear for about 3 minutes, until a nice golden brown crust forms. Patties will not be cooked through, but remove from skillet and set aside.

In the same skillet the patties were browned in, add onions and cook about 5 minutes, until softened and translucent. Then stir in mushrooms and cook until browned, another 3-5 minutes. Once browned, add garlic, and cook about 30 seconds until fragrant.

Add 2 tablespoons of butter into the pan with the onions, mushrooms, and garlic, and stir in the flour.

Cook until the mixture is thick, about 1 to 2 minutes.

Reduce heat to medium low and gradually stir in the beef broth, stirring constantly, until mixture is smooth. Once smooth, add in the Worcestershire sauce, dijon mustard, salt and pepper and bring to a simmer.

Return steak patties to the simmering pan and cover with the gravy. Cover pan with a lid, and cook about 10 minutes, until the steaks are cooked through and the internal temperature reaches 160 degrees F.

Serve immediately over mashed potatoes with the mushroom gravy spooned over top. Enjoy!