Salisbury Steak with Mushroom Gravy

Bahan-bahan (4 porsi)

• 1 1/4 pounds ground beef (90% lean)
• 1/3 cup breadcrumbs
• 2 tablespoons onion (minced)
• 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)
• 1 pinch salt (to taste)
• 1 pinch cracked pepper (to taste)
• 2 teaspoons olive oil
• 1 tablespoon butter
• 1/2 cup sliced onion
• 8 ounces sliced mushrooms
• 1 pinch salt
• 1 pinch pepper
• 1 1/2 cups beef broth
• 1 tablespoon ketchup
• 2 teaspoons Worcestershire sauce
• 1 tablespoon cornstarch
• 1 tablespoon parsley (chopped)