Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain and reserve.
In a large frypan, heat oil over medium-high heat. Add chicken and saute until cooked through and no longer pink inside. Add garlic to frypan; saute until golden. Add cream and spaghetti sauce to frypan; cook over medium heat for 10 to 15 minutes or until sauce thickens.
Add cooked chicken and spinach and cook until spinach reduces. Then add rigatoni; toss with cheese and serve.