Never have button mushrooms been more delicious than in this veg-packed spicy dip recipe, also ideal as a sandwich spread or finisher for simply prepared vegetables.
The aioli will appear quite tight when all the oil is incorporated, but it will loosen to a pourable consistency once the buttermilk and shallot are added.
The key to this sauce is a creamy emulsion of the oil, cheese, and pasta water. Toss and stir—and stir and toss—adding liquid freely, until it comes together.
