In a large stock pot over medium heat, heat the avocado oil and saute the onion, celery, carrots, and garlic. Cook until tender, which will be about 6 minutes.
After those vegetables are tender, sprinkle the gluten-free flour over them.
Also, add the seasonings at the same time. Give it a stir to incorporate the flour into the remaining oil.
(If it seems too dry, you can add another tablespoon of avocado oil at this point. )
Continue stirring while it cooks for 3 minutes. Be careful not to burn the GF flour.
Next, carefully pour the chicken broth into the pot.
( Pro tip: If using store-bought chicken broth from a quart container, you can pierce a hole on top of the carton to make an air vent, so it pours more easily.)
Turn the heat to high and bring everything to a boil.
Once the soup is boiling, add your gluten-free noodles.
Turn down the heat to a simmer and continue cooking for the suggested time that your GF noodle package suggests.
After the noodles are cooked to al dente (tender, but firm), turn down the heat to low.
Stir in the diced, cooked chicken to the soup pot.
Carefully, (it's hot!) taste test the soup at this point. See if you need more salt or other seasonings. Remember, every broth is different and you just need to adjust to taste.
If all tastes good, remove from heat. If it needs a little more nudge of this or that, add it now. Then remove the soup from the heat.
Once the stock pot of soup is removed from the heat, stir in the heavy cream. (Or you DF alternative.)
Let it cool down for about 5 minutes.
Then add the finishing touch of half the juice of one lemon, and stir all to combine. (It's important to wait for it to cool a little so it doesn't curdle the cream.)
Serve immediately with some fresh bread or crackers, and enjoy!