This is my take on the many mixes and premade products that combine chicken, pasta and a creamy sauce. Mine is much lower in fat, sodium, free of weird chemicals and costs only about $4 to make a generous family sized pot.
Heat oil in a large, heavy pot over medium until it shimmers. Add carrots, onion and celery. Cook, stirring frequently, until the carrots are nearly tender.
Add pasta and just enough water to cover. Bring to a boil and cook, stirring frequently, until pasta is tender. Add chicken.
Stir milk into cornstarch in a small bowl until smooth. Add to the cooking mixture, stirring thoroughly. The sauce should begin to thicken almost instantly. Do not stop stirring until it’s thickened and smooth or you’ll end up with a gloppy mess. Make sure you’re stirring clear to the bottom. When it thickens the sauce will be creamy and resemble white gravy.