E.P.
Try substituting low fat or non fat Greek yogurt in your dressing. Thin it out with a little vinegar & a touch of olive oil. Add FRESH dill and/or other herbs along with salt & pepper to taste. I used to make a green goddess dressing with yogurt, olive oil, vinegar, flat leaf parsley, dill, cilantro & chives. I just ran it all through a food processor and added salt & pepper to taste. You could also add garlic if you'd like, although I don't care for it.