Cut out and discard the cabbage core; cut the leaves into 3/4 inch thick ribbons. Place the cabbage in a large bowl.
Thinly slice the cucumber into rounds.
Quarter and deseed the lemon. Juice all four lemon wedges into a bowl.
After peeling and chopping the shallot place into the bowl with lemon juice. Add the creme fraiche, mustard and parmesan to the bowl with shallot-lemon juice mixture
Slowly stir in one tablespoon of olive oil until well combined. Season with salt and pepper to taste.
Mix dressing with the salad and enjoy