Boil Jumbo Shells according to package.
Drain and set aside covering with a wet paper towel to keep from drying.
Brown ground Meats in a skillet together over medium heat with diced Onion.
Cook until no pink meat remains.
Drain any excess fat.
Thaw Spinach in a colander under warm water.
Press to remove excess water.
In a large bowl, mix together Parmesan Cheese, Ricotta Cheese, Spinach, Meat, Onions and spices including Salt and Pepper.
Take Meat and Cheese Mixture and gently stuff into Shells.
Line a large baking pan or two smaller baking pans with Shells (freeze one pan)
Cover Shells with Tomato Sauce.
Top with slices of fresh Mozzarella.
Bake at 375º for about 20-25 minutes or until Cheese is melted and Sauce is bubbling in the center.
Garnish with fresh Parsley before serving.