Step 1

In a large bowl, combine the beef, breadcrumbs, egg, Worcestershire sauce, salt and pepper, using your clean hands. Divide into 6 equal pieces and form each one into oval patties.

Step 2

In a large skillet add the olive oil and butter and heat until melted over medium-high heat. Add the meat patties and fry on both sides until no longer pink in the middle, about 5 minutes per side. Transfer the patties to a plate.

Step 3

Reduce the heat to medium and add the sliced onions and cook until softened, about 3 to 5 minutes.

Step 4

Add the mushrooms, if using, and cook for a few more minutes until the onions are golden brown, another 3 minutes.

Step 5

Add the beef broth, tomato paste, soy sauce, and Worcestershire sauce and stir. In a small bowl whisk the cornstarch with a bit of water or beef broth and add to the skillet. Whisk until the sauce thickens, for about 2 minutes.

Step 6

Add the meat back to the pan and spoon gravy over the top. Cook for another minute until the meat patties warm through.

Step 7

Garnish with parsley and serve over mashed potatoes.