Preparation Drape a kitchen towel over a small saucepan; set a small metal bowl over (this will hold bowl in place). Whisk egg yolk*, garlic, 1/4 teaspoon salt, and 2 teaspoons water in metal bowl to blend well. Whisking constantly, slowly drizzle in grapeseed oil, 1 teaspoonful at a time, until sauce is thickened and emulsified. Whisking constantly, add olive oil in a slow, steady stream. Stir in cayenne; season aioli with lemon juice, pepper, and salt. Cooks' Note:*Raw egg is not recommended for infants, the elderly, pregnant women, people with weakened immune systems…or people who don't like raw eggs. But they won't have to forgo this aioli altogether. Just use pasteurized egg yolk instead.