Mozzarella Stuffed-Crust Onion Pie

Ingredients

• – 6 onions, thinly sliced
• – 2 tbsp. Real California butter
• – 1 tsp. concentrated beef stock
• – 1 6-oz. can of tomato paste
• – 6 tbsp. hot water
• – 1 tbsp. dried oregano
• – 1 tbsp. red wine vinegar
• – 1/2 tsp. sugar
• – 1/4 tsp. garlic powder
• – 1/4 tsp. ground cayenne (optional)
• – Salt and pepper
• – All-purpose flour for the work surface
• – 1 16- to 20-oz. pizza dough
• – 1 lb. shredded Real California mozzarella cheese, divided
• – 1 lb. sliced Real California provolone cheese
• – 1/2 lb. shredded Real California Gruyere cheese
• – 2 tbsp. chopped fresh parsley