Cook bacon in a Dutch oven over medium-high heat until crisp. Remove bacon from pan. Reserve 1 tablespoon drippings in pan; discard remaining drippings. Cool bacon, and crumble. Set bacon aside. Add potato and onion to drippings in pan; sauté 3 minutes or until onion is tender. Add flour to pan; cook 1 minute, stirring constantly. Stir in clam juice; bring to a boil. Cover, reduce heat, and simmer 6 minutes or until potatoes are tender. Stir in milk; bring to a simmer over medium-high heat, stirring constantly (do not boil). Stir in thyme, salt, pepper, and fish; cook 3 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness. Stir in parsley. Sprinkle with bacon.