Cook ravioli as directed on package. Drain well. Set aside.
Meanwhile, heat 2 tablespoons of the oil in a large deep skillet on medium heat. Add chicken and cook on each side until browned, about 5 minutes. Remove from pan and allow to cool slightly. Cut into bite-sized pieces; set aside.
Add onions and water to same skillet, scraping brown bits from bottom of skillet. Cook 5 minutes, stirring occasionally, until onions are softened. Add Flavor Cube and remaining 1 tablespoon oil; crush cube with spoon or spatula until crumbled. Stir in sun-dried tomatoes and half-and-half. Return chicken to skillet. Simmer 5 minutes or until sauce is slightly thickened.
Add mozzarella and cooked ravioli, stirring until cheese is completely melted. Serve immediately.