"A lobster roll is a kind of sandwich filled with lobster meat. A traditional lobster roll contains the fresh cooked meat of a one-pound lobster, tossed with mayonnaise and served on a grilled hot dog bun or similar roll, served so that the opening is on the top rather than on the side. The filling may also contain diced celery and/or scallion, or use drawn butter instead of or in addition to the mayonnaise. The sandwich can also contain lettuce and lemon.
Lobster rolls in the U.S. are especially associated with the state of Maine, but are also commonly available at seafood restaurants in the other New England states and on Eastern Long Island in the U.S., where lobster fishing is common. They tend to be virtually unheard-of in landlocked regions (such as the Upper Midwest), where lobster is an expensive delicacy.
They are a staple summer meal throughout the Maritime provinces in Canada particularly Nova Scotia where they may also appear on hamburger buns, baguettes, or other types of bread rolls - even pita pockets. The traditional sides are potato chips and dill pickles.Some McDonald's restaurants in New England and the Canadian Maritimes offer lobster rolls as a seasonal menu item, called the McLobster."