Bridgit introduced me to the dressing we used in this salad and I'm completely hooked. I think I converted the Waldmans last night, too. The dressing is by Annie's Organics and it's tahini-based. It's so creamy I had to check the ingredient list a few times to confirm that it is indeed vegan.
It's mostly tahini, lemon juice, vinegar, and herbs. It was $4.99 at Cronig's (so probably $1.99 off-island) but worth every penny. The spicy watercress was great with it but I think you could put this on pretty much anything and come out with something yummy.