Using a large whisk, combine the egg yolks, garlic, Dijon mustard, lemon juice, 1 teaspoon water, salt and black pepper in a medium bowl. Roll up a kitchen towel and wrap it around the base of the bowl to stabilize it. While whisking constantly, add a few drops of vegetable oil to the egg mixture. Continue adding drops and whisking until the mixture starts to thicken. If the mixture looks well combined, begin to add the vegetable oil in a thin stream, always whisking. Continue with the olive oil. Serve immediately, or cover and refrigerate for up to 4 days.