• 1/2 Hass avocado, coarsely chopped
• 1/4 cup plus 2 tablespoons buttermilk
• 1 tablespoon white wine vinegar
• 1 small shallot or onion, coarsely chopped
• 1 1/2 teaspoons minced flat-leaf parsley
• 1 small garlic clove, smashed
• 1/4 cup vegetable oil
• Kosher salt and freshly ground white pepper

In a blender, combine the avocado with the buttermilk, vinegar, shallot, parsley and garlic and process until smooth. With the machine on, add the vegetable oil in a thin stream and process until smooth. Season with salt and white pepper.