I've started using this recipe for making ranch dip and ranch dressing. It comes from here.
5 Tablespoons dried minced onions
7 teaspoon parsley flakes
4 teaspoon salt
1 teaspoon garlic powder
Dip: Mix 2T seasonings with 1 c mayo and 1 c sour cream (I prefer all sour cream).
Dressing: Replace some of the sour cream with some buttermilk or milk to make it a little thinner.
You really have to let this sit for a while to get the full flavor. Make it a couple hours ahead. Note that it will thicken a little bit as the onions and herbs hydrate.
