In a large pot or Dutch oven, melt butter over medium heat. Add onion and celery and cook until softened, about 5-7 minutes.

Add chicken broth, thyme, and bay leaf. Bring to a boil, then reduce heat and simmer for 10 minutes.

Add corn and simmer for another 5 minutes.

Gently add cod fillets to the pot and cook for 3-5 minutes, or until the fish is cooked through and flakes easily with a fork.

Stir in heavy cream and season with salt and pepper to taste.

Remove bay leaf before serving.