Hands On: 10 minutes Total: 25 minutes Cook chicken and onions in large nonstick saucepan over medium-high heat 5 minutes, or until chicken pieces are no longer pink in centers and onions are crisp-tender. Stir in water and tomato paste. Add noodles; stir. Bring to a boil over high heat. Reduce heat to low; simmer 10 to 12 minutes, or until noodles are tender. Add Alfredo sauce and spinach; mix well. Cover pan with lid. Cook over medium-low heat 3 minutes, or until spinach is wilted and sauce is heated through, stirring after 1 1/2 minutes.