Salisbury Steak with Mushroom Gravy

Name: Salisbury Steak with Mushroom Gravy
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: American
Ingredients: 1 1/4 pounds ground beef, (90% lean); 1/3 cup breadcrumbs; 2 tablespoons minced onion; 1 teaspoon Italian seasoning, (or equal parts dried basil, dried oregano and dried thyme -- OPTIONAL); 1 tablespoon ketchup; 2 teaspoons Worcestershire sauce; 1 large egg, (beaten); salt and pepper to taste; 2 teaspoons olive oil; 1 tablespoon butter; 1/2 cup sliced onion; 8 ounces sliced mushrooms; salt and pepper to taste; 1 1/2 cups beef broth; 1 tablespoon ketchup; 2 teaspoons Worcestershire sauce; 1 tablespoon cornstarch; 1 tablespoon chopped parsley