Step 1

Make a quick mayonnaise: Pulse the egg yolk, Dijon mustard, and lemon juice in a blender with a few quick pulses. Turn the blender on and drizzle in the oil in a thin, steady stream. Continue to blend until the mixture is light in color and thick.

Step 2

Blend the herbs and garlic: Stop the blender and scrape down the sides. Add the parsley, chives, tarragon, anchovy paste, and garlic. Blend until smooth and vibrant green.

Step 3

Whisk the dressing with the yogurt: Place the Greek yogurt or sour cream in a medium bowl. Add the herb mayonnaise and stir to combine.

Step 4

Taste and season: Taste the dressing for seasoning. The anchovy paste is usually salty enough, but add additional salt if desired.

Step 5

Serve: Serve as a dip for crudité or as a dressing for salads.