Mix all filling ingredients together in a large bowl.
Preheat oven to 375 degrees F.
Cook shells per package directions; drain. Place on a large plate or baking sheet to cool. Toss with about 1 tsp olive oil so the don’t stick to each other or the dish.
Mix the alfredo sauce with the chicken stock—ONLY IF USING STORE-BOUGHT SAUCE. Place about 1/2 cup in the bottom of a 13 x 9-inch baking dish, spreading the sauce to coat the entire bottom of the pan.
Fill shells and place them in the pan on a slight diagonal.
Top with the remaining sauce.
Bake for 35 minutes, or until sauce is bubbly and stuffing is cooked.
Top with additional bacon and parsley