1. Heat the extra virgin olive oil in a Dutch oven or large soup pot over medium heat then add the carrots, celery, and shallots or onions. Season with salt and pepper then saute until the vegetables are tender, 8-10 minutes.
2. Add the chicken stock or broth to the pot then turn the heat to high, place a lid on top, and bring to a boil. Once boiling, add the chicken breast halves then place the lid back on top. Turn the heat down to low then simmer until the chicken breasts are cooked through, 10-12 minutes. Transfer the cooked chicken breasts to a cutting board then, once cool enough to handle, chop or shred. Place chicken inside a bowl or storage container then refrigerate until ready to add back into the soup.
3. Meanwhile add the rice to the pot then stir to combine. Place a lid on top then simmer until the rice is al dente, 20-30 minutes depending on the brand, stirring occasionally.
4. When the rice has 10 minutes or so left to simmer, melt the butter in a small saucepan over medium heat. Sprinkle in the gluten free flour then cook while whisking for 1 minute. Slowly drizzle in the milk while whisking to create a smooth sauce then switch to a spatula and cook while stirring until the mixture is thick and creamy, 1-2 minutes. Remove the pan from the heat then place a lid on top and set aside.
5. Once the rice is al dente, slowly stream in the butter/flour/milk mixture while whisking the soup constantly. Add the chicken then cook for 5 more minutes, stirring frequently, or until the soup has thickened and the rice is tender. Taste then add more salt and pepper if necessary. Remove the pot from the heat then let it sit for 5-10 minutes to thicken slightly before scooping into bowls then serving.

Recipe source: https://iowagirleats.com/chicken-wild-rice-soup/