Toss the shredded cabbage and 2 teaspoons of salt in a colander or large mesh strainer set over large bowl. Let it stand until the cabbage wilts, at least 1 hour or up to 4 hours. Rinse the cabbage under cold running water. Press, but do not squeeze, to drain; pat dry with paper towels. Place the wilted cabbage and carrot in a large bowl.
PREPARE THE DRESSING:
In a small bowl, whisk together the buttermilk, mayo, sour cream, parsley, shallot, vinegar, sugar, mustard, 1/2 teaspoon salt, and pepper together in small bowl. Pour the dressing over the slaw and toss to combine; refrigerate until chilled, about 30 minutes. (the coleslaw can be refrigerated for up to 3 days.)
*For accurate WW points, use light mayo and light sour cream.
*To save time, buy the bagged coleslaw mix to use instead of shredding it yourself.
*If you are preparing this recipe as GLUTEN FREE, just make sure the brands of Dijon and mayo you're using are designated as GF.