My husband is a big chicken pot pie fan. We have been trying to eat better and realized how many calories are in one pot pie! Yikes! This soup has all the creamy goodness of a pot pie, but with a fraction of the calories.
In a small bowl, whisk together flour and 1/2 cup of the water until blended. Set aside.
Pour remaining water and milk into a large pot and bring to a boil. Add celery, onion, frozen vegetables, potatoes and mushrooms.
Bring to a boil then simmer on low until vegetables are soft, about 20 minutes. Add bouillon, thyme, chicken and salt and pepper. Whisk in slurry. Stir and cook another 2-3 minutes until soup thickens.