The lemon yogurt adds so much flavor and is the key to this dressing. The salad is simply delicious and easy to make. You can make this ahead, cover and chill for up to 6 hours, but do not stir in the walnuts until you are ready to serve it. You may substitute pears for apples for something different. I think it tastes best with fresh pineapple and apples. My GF gave me this recipe that she found in Dieter’s Cookbook by Better Homes and Garden. To save time I purchase the fresh pineapple already peeled from the grocery store.