Start by heating 2 tablespoons of oil in a skillet over medium. Sauté the finely diced onion for 4 minutes until soft, then add garlic for about 1 minute until fragrant. Set it aside to cool.

In a large bowl, combine that sautéed mix with ground beef, panko, egg, tomato sauce, mustard, Worcestershire, oregano, pepper, and salt. Mix gently with your hands—don’t overwork it to keep the patties tender.

Shape the mixture into 4 or 5 even oval steaks. Brown them in the same skillet with the remaining oil, about 1 minute per side. Set them aside.

In that same flavorful pan, cook sliced onions until golden. Add mushrooms, stir until soft. Pour in the beef broth, seasonings, and bring it to a boil.

Add the patties back into the skillet. Cover and let them simmer in the broth for 15 minutes. While they finish, stir together cornstarch and water to make a slurry, then slowly pour it in. Stir for 5 more minutes until the gravy thickens and the patties hit 160°F.