In a large Dutch oven or your favorite soup pot cook the bacon until done. Remove the bacon to cool, leaving bacon grease in bottom of pan.
Sauté onions and celery in pan until soft.
Add potatoes, broth, salt, thyme and pepper. Cover and cook for roughly 15-20 minutes, or until the potatoes are tender.
Stir rice flour into ½ cups of milk until smooth. Add to remaining 1 ½ cups milk and whisk until smooth. Rice flour easily clumps, so you may need to add small amounts of flour to the milk at a time. If you want to substitute corn starch for rice flour you can.
Add milk to soup pot and stir. Add remaining milk until desired consistency is reached.
Lay skinned fillets on top of the chowder, cover and let simmer for 8-10 minutes or until fillets easily break apart. Once fish is cooked, stir until fish is even distributed throughout the soup.