In a heavy bottom pot, cook bacon until crispy. Remove bacon pieces and set aside. Add potatoes, onions, bay leaf, and thyme sprigs to pot and cook over medium heat until onion is just tender. Dust with flour and cook 1 minute until bubbly.

Whisk in milk and cream. Bring to a gentle boil, then reduce heat to medium-low and cook until potatoes are just tender.

Add in cod fillet and gently simmer for 5-6 minutes more until fish is cooked through and flakes easily with fork. Remove bay leaf. Season with salt, pepper and cayenne.

Serve in bread bowls, sprinkle tops with crispy bacon and sliced scallions.