Sprinkle salt over the cucumber pieces; allow to sit 1 hour. Strain liquid from cucumbers.
Combine the cream, mustard and tarragon in a saucepan over medium heat; add the cucumbers and simmer 8 minutes.
Pour the wine into a large frypan over medium heat. Season with salt and add the bay leaf. Bring the wine to a boil. Lay the fish in the frypan, reduce heat to medium-low and cook until the fish flakes easily with a fork, 8 to 10 minutes. Serve fish with cucumbers on the side.