This variation on a traditional Provençal sauce is worlds away from store-bought mayonnaise. Use this assertively flavored condiment on sandwiches to give them a garlicky kick; use it as a dip for roasted eggplant or zucchini, or even just celery and carrot sticks; and use it judiciously on side dishes like roasted potatoes to give them a leg up.
In the bowl of a food processor, combine the egg yolks, garlic, and lemon juice. With the motor running, slowly add the vegetable oil and truffle oil. If the mixture appears too thick (similar to a mayonnaise), add 1 tablespoon of water at a time to thin out. Season with salt and pepper, to taste. Refrigerate until needed.