Preheat oven to 350 degrees.

Boil water and cook shells according to package directions. Drain and set aside.

Cut the chicken breasts into chunks and cook on medium heat in olive oil.

When the chicken is cooked, chop into smaller pieces.

In a medium bowl, mix ricotta and chicken.

Fill each shell with a rounded tablespoon of the ricotta/chicken mixture.

Pour ¼ cup of alfredo sauce into a 9x13 casserole dish and spread to cover the bottom. Fill the casserole dish with the stuffed shells.

Pour ¾ cup of alfredo sauce over the stuffed shells. Cover with foil and bake in a 350 degree oven for 30 minutes.

Remove from oven and add 1 cup of shredded mozzarella on top. Bake for 15 minutes uncovered.