01 -
Start by sautéing the diced onion in a skillet over medium heat until soft and translucent, about 4 minutes. Add minced garlic, cook for another minute, then set aside to cool slightly.
02 -
In a large bowl, combine the cooled onion mixture with ground beef, breadcrumbs, egg, tomato sauce, mustard, Worcestershire sauce, oregano, pepper, and salt. Mix gently just until combined, then shape into 4-5 oval patties.
03 -
Heat vegetable oil in your skillet over medium heat. Brown the patties for about 1 minute per side until golden. They won't be fully cooked yet - transfer them to a plate.
04 -
In the same skillet, add more oil if needed. Cook sliced onions until browned, then add mushrooms and cook until they turn golden. Return the patties to the pan.
05 -
Pour in beef broth and add onion powder, garlic powder, and Worcestershire sauce. Bring to a boil, then reduce heat, cover, and simmer for 15 minutes.
06 -
Stir in the cornstarch mixture and cook, stirring gently, for about 5 minutes until the gravy thickens. Season with salt and pepper to taste. Make sure patties reach 160°F internal temperature.