In a large mixing bowl, combine the ground beef, breadcrumbs, minced onion, egg, Dijon, salt, oregano, and black pepper. Shape mixture into four 5¾-inch oblong patties.
1½ pounds lean ground beef, ½ cup breadcrumbs, ¼ cup minced onion, 1 large egg, 1 teaspoon Dijon mustard, 1 teaspoon kosher salt, ½ teaspoon dried oregano, ½ teaspoon ground black pepper
Heat 1 tablespoon of olive oil in a large skillet set over medium heat. Fry the beef patties for 4-6 minutes, flipping once, until browned on both sides. Transfer to a plate and cover with foil.
1 tablespoon olive oil
To the skillet, add the beef broth, Worcestershire sauce, onion, and mushrooms. Bring the mixture to a boil, then return the patties to the skillet and cover it. Reduce the heat to low and simmer for 10 minutes. Transfer to a plate and cover with foil.
2 cups low-sodium beef broth, 1 teaspoon Worcestershire sauce, 1 yellow onion, 8 ounces cremini mushrooms
Turn heat to medium, bringing the skillet mixture to a boil. In a small bowl, mix the cornstarch and water, then stir it into the onion mixture. Cook for 1-2 minutes, stirring frequently, until the gravy is thickened, tasting and adjusting seasoning as desired. Pour over the steak patties and serve.
3 tablespoons cornstarch, 3 tablespoons water