Make the Base - In a medium bowl, whisk the egg yolk, then mix in 1 teaspoon of lemon juice and mustard. Gradually whisk in a few drops of olive oil until ¼ cup is reached. It should start to thicken and lighten in color. Add 1 teaspoon of lemon juice while mixing. Gradually whisk in ¼ cup of olive oil, followed by the last 1 teaspoon of lemon juice. Slowly whisk in the remainder of the olive oil.
Make the Dressing - In a blender or food processor, add the base, avocado, parsley, chives, green onions, tarragon, garlic, anchovies (if using), water, apple cider vinegar, salt, and pepper. Blend on medium speed until smooth, about 1 minute. Season with more salt and pepper to taste.
Notes
Recipe Yields: 1 1/3 cups of dressing
Serving Size: 1 tablespoon
Storing: Place inside an airtight container in the fridge for up to 5 days.
Anchovy Substitute: Add 1 teaspoon anchovy paste. Alternatively, use 1 teaspoon of Worcestershire sauce, soy sauce, miso paste, kalamata olives, or capers.
Mayonnaise Substitute: Use 1 cup of store-bought mayonnaise for the egg yolk, mustard, lemon juice, and olive oil.
Thin the Dressing: Add 1 tablespoon of water at any time. Blend and adjust the vinegar, salt, and pepper amount.
Make it Vegan: Use vegan mayonnaise or substitute 1 additional cup of avocado for the mayonnaise. Replace anchovies with 1 teaspoon miso paste or omit. Adjust seasonings to taste.
Make it Whole30: Substitute kosher salt with sea salt. Replace Dijon mustard with mustard powder.