Add everything but the herbs in to a food processor or blender. Then, rough chop the herbs into 1in (2.5cm) sections, so they don’t get wrapped around the blade. Next, toss those chopped herbs into the food processor as well.
Blend until you can see the dressing turn green and the herbs become whipped into very small pieces. That's it. It's that easy.
Notes
As far as I'm concerned the last 5 ingredients in this recipe (garlic and herbs) can be measured with your heart. I have done more and less of each of those ingredients and it still turns out delicious every time.
Feel free to leave out herbs you don't like and add in others, like parsley, tarragon, spinach, or chives. Have fun with it! Just remember, try to keep your experiments complimentary to whatever else you are eating.
Green Goddess Dressing is good for up to a week, if stored in an airtight container in your refrigerator.
I do not recommend freezing Green Goddess Dressing. The cells in mayo, sour cream, and fresh herbs will all expand when frozen and produce a brown watery concoction when de-frosted. (bleh!)