Cook the chicken and make the sauce if not already done.
Heat a large pot of water until boiling. Cook the jumbo shells until al dente as per package direction, approximately 10 minutes. Drain and set aside.
While the shells are cooking, make the cheese mixture by combining all of the ingredients.
Shred or dice the chicken. Add the chicken to the cheese mixture and stir to combine. Add additional chicken if desired. Set aside.
Heat the oven to 375 F.
Place a little of your sauce in the bottom of your baking dish to cover. Using a spoon, scoop approximately 1.5-2 Tablespoons of the chicken and cheese mixture into each shell. Place the shell in the baking dish, open side up.
Repeat with the remaining cheese mixture and shells.
Cover the shells with the Simple Marinara Sauce, 3/4 cup mozzarella, and 1/4 cup Parmesan cheese. Bake at 375 F until the cheese is melted and starting to brown on top, approximately 20 minutes.
Garnish with additional fresh basil if desired and serve immediately.
Notes
I love to use my Simple Marinara Sauce for this recipe but use anything you like or have.For a meat heavy dish, use more chicken as desired.The exact number of shells will vary based on how much you stuff them and how much chicken you use.