Set down two layers of paper towels. Place shredded kohlrabi on top of the paper towels. Wrap up and squeeze out the moisture. Place the squeezed-dry kohlrabi and shredded apple together in a bowl and toss.
In another bowl, whisk the cream until it holds soft peaks; whisk in the lemon juice, mustard, parsley, sugar, salt and pepper to taste. Pour over the shredded mix, and toss to mix well. Serve.
Notes
Try subbing sour cream or plain yogurt for the heavy whipping cream. You'll get a bit of different flavor, but you'll save on the fat calories.
Add amount of dressing desired, to taste. You may wish to have it very creamy (using it all) or minimally dress it using just a portion of the dressing.