I seem to recall this being a staple in our house when I was little... but I didn't really care for dressing then so I don't have a flavor memory for it. Recently it's been crossing my path and I decided I wanted to give it a try. I scribbled down this outline from I-don't-recall-where. Last time I was at the local Mediterranean grocery, I was able to grab all the herbs mentioned for under $2... but I'm sure others could be swapped in (I'm putting in a good handful of basil from my garden next time!).
1/3 c chopped chives (I used garlic chives because that's what I found... they are larger than "regular" chives and are flat rather than round)
1/3 c chopped parsley
1 T chopped tarragon - you want to chop this as finely as you can before putting in the food processor (too tough to process well)
2 anchovy fillets
3/4 t salt
1/4 t garlic powder
1/4 t pepper
3 T lemon juice
Some combo of dairy, mayo, &/or chopped avocado to make up the body of the dressing*
Whir herbs, anchovies, garlic powder, salt & pepper in a small food processor until finely chopped, scraping down sides as needed. Add lemon juice and whir. Add dairy/mayo/avocado and whir until smooth.
*For my first batch, I used 2 modest soup spoons of Miracle Whip, 3 modest soup spoons of sour cream, and a good-sized avocado. I really liked the vinegar hit from the Miracle Whip and if I make this again without it, I will add a tablespoon of vinegar to bring that component in. My amounts made a little over 1.5 cups of dressing.