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