The depth and breadth of what a sandwich can contribute to a day cannot be overstated. A great sandwich is a sum of lovingly compiled ingredients that leaves a diner with a Gene Kelly spring in his step. Imagine, then, what the lobster roll from the Smack Shack — somewhere in the stratosphere above "great" — can do for you. A roll of split, butter-redolent bread is crammed with chunks of tender lobster that have been mixed with crunchy cucumber in a lemon-tarragon aioli. Each bite is as bright as a seaside morning, decadent and rich. It's a food truck sandwich so delicious we demand it year-round. Whether it's eaten from the side of the truck in summer or in the cozy confines of the delightfully divey 1029 Bar in winter, it's a sandwich worth seeking out and impossible not to savor.