Still, when it comes to those late-night creations, whether at work or at home, we use quality fillings, from homemade aioli to bakery-fresh loaves. We reach for the pork tenderloin from last night's dinner, a half-eaten rotisserie chicken—foods we'd want to consume with or without two slices of bread. Eight years ago, when we created 'wichcraft, our New York City-based chain of sandwich shops, it was with that principle in mind. We choose ingredients that lend the right balance of acid, sweetness, salt, and, sometimes, spice, the same way we design a dish for a restaurant. Sauteed black trumpet mushrooms add an umami note to grilled cheese. Pickled red onions and roasted tomatoes are bright counterpoints to a creamy chicken salad sandwich. Then there's texture: A slaw or salad green introduces bite; avocado, mayonnaise, or a poached egg lends a creamy mouth-feel. One of our favorite sandwiches is a calamari sub that embodies all of these qualities: The richness of the fried seafood is cut by the acid from the lime juice and the heat from the chiles; cilantro and fennel bring fragrance and sweetness; cucumber adds crunch to the soft potato roll and the tender squid.