Salisbury Steaks

Ingredients

• 1 cup onion
• 4 TBSP uncooked rice
• 1/4 tsp salt
• 1/4 tsp pepper
• 2 egg whites
• 1 pound lean ground beef
• 6 tsp olive oil, divided
• 1 1/2 cups fresh mushrooms
• 2 cups beef broth
• 4 tsp Worcestershire sauce
• 2 TBSP cornstarch
• 2 TBSP water