Melt butter in large stockpot over medium heat. Add onion, carrots and celery and cook stirring occasionally until tender, about 3-4 minutes. Stir in thyme, stir until fragrant
Continuously Whisk in flour until lightly browned. Gradually whisk in chicken broth and milk and cook whisking constantly until slightly thickened (about 2 minutes) Stir in potatoes
Bring to a boil and reduce heat to a simmer. Continue simmering until potatoes are cooked. (10-12 minutes) Sir in chicken and cheese a little at a time until smooth. Season with salt and pepper to taste.
If chowder is too thick add additional milk until desired consistency.
Serve immediately
Recipe by The Gingham Apron at https://www.theginghamapron.com/cheesy-chicken-potato-chowder/