Chicken and Spinach Stuffed Shells

This is absolutely delicious! I loved this dish and so did my whole family. I made this in AZ for Christine's baby blessing dinner and it was a huge hit. Again, a bit time consuming, but so worth it. We had 10 adults eating this and there were still left overs, so it makes a lot! It can also be frozen though and reheated later.

Source: The sisters cafe blog

44 uncooked jumbo pasta shells (That’s about one and one-half 12-oz boxes)
2 c chopped cooked chicken
2 c fresh chopped spinach
1 onion, chopped
2 cloves garlic, minced
1 (15oz) container ricotta cheese
2 (8oz) packages cream cheese, softened
1 (5oz) package shredded Parmesan cheese (about 1 2/3 c.)
1 large egg, lightly beaten
1 Tb dried parsley flakes
1 tsp Italian seasoning
1/2 tsp salt
1/2 tsp pepper
2 c shredded mozzarella cheese, divided
1 (26oz) jar prepared spaghetti sauce (any variety)

Cook shells according to package directions (be sure to stir every once in awhile so they don't stick to the bottom of the pan and tear apart); drain and set aside.
Preheat oven to 350°. Lightly grease 2 13x9x2inch baking dishes.
In a large bowl, combine chicken and all the rest of the ingredients except mozzarella and spaghetti sauce. Stir in 1 cup mozzarella. Spoon into shells. Spread half of spaghetti sauce into prepared baking dishes. Arrange shells over sauce; top with remaining sauce. Cover tightly with heavy-duty aluminum foil. Bake, covered, for 40 minutes. Uncover, sprinkle with remaining 1 cup mozzarella. Bake for 5 to 10 more minutes.
Makes 8-10 servings.