Saute onions, celery, carrots, and butter until veggies soften. Add chicken base and flour and mix.
Over medium heat, add the milk slowly using a whisk and stirring constantly. Heat soup so that it thickens. Be sure to stir during this process and do not heat too fast (you don’t want the roux to burn). Also, do not let the soup boil as it will curdle if heated too much (165°F is fine).
Puree the soup in batches in a blender.
Add the corn and its juice, sliced potatoes, and chicken and heat to 165°F.
