Chicken Breast Meat in Alfredo Sauce on Rigatoni Pasta with Parmesan Cheese and Parsley, Chicken Alfredo

alfredo sauce (milk, sour cream [cultured grade a milk, grade a cream contains less than 2% of modified food starch, sodium phosphate, guar gum carrageenan, soidum citrate, locust bean gum, potassium sorbate, parmesan cheese [pasteurized milk, salt, powdered cellulose, natamycin, unsalted butter [cream, natural flavoring, olive oil, white flour, garlic, pasta rigatoni, grilled chicken (chicken, water, contains 20 or less of the following: carrot powder, chicken stock, garlic powder, maltodextrin, natural flavor, rice starch, salt, sugar, vegetable stock [carrot, onion, celery, vinegar, parmesan cheese (pasteurized milk, salt, powdered cellulose [added to prevent caking, natamycin, parsley