I tend to use fresh ingredients whenever possible, but in this recipe, dried herbs and onion and garlic powder are key. It gives the dressing a classic "restaurant" flavor.
Substitutions
Regular mayo and yogurt work well too.
Everything can be modified to taste. Increasing the ratio of mayo to yogurt will make a thicker dip.
There are soy and egg free mayos available but currently all have some form of corn in them. If not avoiding egg and soy, you may be able to find a mayo that is corn free.
Coconut: Although classified by the FDA as a tree nut, coconut is not a common allergen and is not related to tree nuts. If you have a tree nut allergy, consult your physician to find out if you need to avoid coconut.
Egg Substitutions: There are many egg-free products and foods available to make your recipes free of eggs. Find out more about egg substitutions.
Milk and Soy Substitutions: Alternative dairy-free milk beverages and products will work in most recipes. Find out more about milk substitutions and soy substitutions.