Fill a pot with water and add the carrots, celery, and onion. Bring to a simmer and cook until the vegetables are soft, about 20 minutes. Once done, reserve 4 cups of the vegetable cooking water. Then, remove the vegetables from the pot and set them aside.
In a separate pot, fill with water and add a pinch of salt. Bring to a boil, then add the pasta. Cook according to the package instructions, approximately 12 minutes. Before draining, reserve 1 cup of the pasta water.
For the full step-by-step instructions and video tutorial, download the Little Lunches app.
