PREPARATION :
Preheat oven to 350°F.
Combine ground beef, breadcrumbs, egg, onion flakes, garlic powder, salt and pepper together in an large bowl. Mix until well combined. Evenly divide beef into 4 servings. Gently roll each into a ball and press down slightly to flatten into a thick patty.
Add cooking oil to a large ovenproof skillet on medium-high. Brown patties in skillet on both sides then remove and set aside on a platter.
In the same skillet, reduce heat to medium and add butter, onions, and mushrooms. Season with a pinch of salt and pepper. Sauté for 3-5 minutes or until mushrooms are softened and onions are tender.
Add flour and stir for 2 minutes, or until flour has created a roux. Add beef stock and stir to loosen up any bits of flavor in the skillet. Bring mixture up to a boil.
Reduce heat to a simmer and add beef patties back into the skillet, spreading evenly around the pan. Place skillet into preheated oven to cook for 25-30 minutes, or until patties are cooked through.
Serve each patty topped with mushroom and onion gravy. Enjoy!
