In the base of a large Dutch oven or heavy-bottomed pot, heat the olive oil over medium heat. Add the chicken breast pieces and cook for a few minutes until just browned on both sides. The chicken won’t be cooked yet, but that’s okay. Remove the chicken from the pot and set aside.

Add the onion, carrots, celery, and garlic into the pot and sauté for a few minutes until softened, using a wooden spoon to scrape any browned bits of chicken from the bottom of the pan.

Add the chicken stock to the pot with the vegetables and add back in the chicken pieces. Turn the heat down to low and simmer with the lid on for 10 minutes or until the chicken has cooked through.

Remove the cooked chicken and set aside on a chopping board. Chop into small pieces.

To the soup, add in the dried pasta and allow to gently simmer for about 10 minutes or until just cooked.

While the pasta is cooking, make the white sauce. In a small saucepan over medium heat, melt the dairy-free butter. Add in the plain flour and mix, cooking for a minute or two. Slowly add the oat milk a little at a time, mixing well between each addition, until the mixture resembles a thick and creamy sauce.

When the pasta is almost done cooking, add the chopped chicken back to the pot along with the white sauce. Mix well, letting the soup cook for a few more minutes until combined and thickened. Stir through the chopped parsley and taste, seasoning with salt and pepper.