Cook pasta according to package directions. Meanwhile, heat cream and butter in a large saucepan until butter melts. Add cheese; cook and stir until melted. Rinse and drain pasta; add to cheese mixture. Cover and keep warm. In a skillet over medium heat, saute onion and garlic in 3 tablespoons oil until onion is tender. Add squash; cook until tender. Add 1 teaspoon salt and pepper; remove and keep warm. Add remaining oil to skillet; cook chicken with herbs and remaining salt until juices run clear. Place pasta on a