If you can’t find Lancaster Cheddar from Pennsylvania in your market, consider some award-winning substitutes, such as Fiscalini Bandaged Cheddar from California or Grafton Cheddar from Vermont.

THE AIOLI: In a mixing bowl, blend the vinegar, garlic, and mustard. Whisk in the egg, combining well. Whisking vigorously, add the oils, a few teaspoons at a time, until the mixture is thick and creamy. Stir in chopped herbs. (Aioli may also be made in a food processor.)

THE SANDWICH: Split the roll and spread each cut surface with the Truffle Aioli. Layer the sandwich with the tomatoes on the bottom, then the chicken, cheddar, arugula, and pepper.

DO-AHEAD: The aioli may be made the day before serving but should be kept covered and refrigerated.

CHEATS: For a quick sandwich condiment inspired by Harris’s aioli, try flavoring your favorite mayo with a pinch of truffle oil, good mustard, and finely chopped fresh herbs, such as those used in this recipe.

NOTE: As in most classic aioli recipes, Harris uses raw egg as an emulsifier. While proper care and handling of fresh eggs makes this a safe practice, public health experts caution pregnant women, older people, very young children, and those with impaired immune systems to avoid consuming raw eggs to avoid possible food-borne illness.

By Jenny Harris, executive chef at Tria in Philadelphia
Photography by Alison Miksch