When I visited A Bolota, a lovely restaurant perched on the sweeping plains of the eastern Alentejo, this dip, called pate de azeitonas verdes, was brought to our table. As I nattered away with friends, I dipped, spread, and nibbled, until I realized I alone had eaten all of it. Later, when I became friendly with the cook, Ilda Vinagre, I watched her make it and was flummoxed when she whipped up its silky base: milk “mayonnaise”—whole milk whirred into a smooth consistency with the addition of vegetable oil. I serve this as a dip with a platter of crudites, alongside crackers or bread, or, sometimes, as a topping for grilled fish.—David Leite