Cook bacon in medium dutch oven over medium heat until crisp.
Remove bacon from pan, reserving 1 teaspoon on bacon grease.
Crumble bacon and set aside.
Add onion, celery, salt, thyme, and garlic to drippings and cook for 4 minutes or until vegetables are tender.
Drain clams (set clams aside), and add clam liquid, clam juice (or fish stock), potatoes and bay leaf to pan. Bring to boil and then reduce heat and simmer for 15 minutes or until potatoes are tender.
Combine flour and milk in bowl and whisk until smooth.
Add flour-milk mixture to pot, return to boil and then reduce heat and simmer for 12 minutes or until thick.
Add clams and continue cooking for 2 minutes.
Sprinkle with bacon and serve.