The thrill of discovery is finding a superb lobster roll on the winding back roads of South San Francisco.

Twenty-five-year-old retail shop New England Lobster Co. has long been a secret seafood source for displaced East Coasters. Now, with the recent addition of a food truck in the parking lot, it's a lunch destination too.

Weekdays you can get a lobster roll ($15.50), the fresh-picked meat lightly mixed with mayonnaise and piled onto a buttered, griddled, top-loading bun, as dictated by Pine Tree State tradition. At the condiment bar, add diced celery or red onion if you wish, though we think it needs no adornment.

The same treatment is also given to crab meat ($14), and both rolls come sided by coleslaw and a bag of chips.

The truck's offerings are rounded out by a lobster-and-corn chowder ($5 for a cup; $8 for a bread bowl), more like a bisque that's been hot-rodded with chunks of claw and tail meat and kernels.

Free from the buoy-based décor and preppies in pink that characterize so many East Coast "fish shacks," you may be convinced that what New England Lobster Co. is serving can't possibly be authentic. But one bite will convince you you're wrong.

New England Lobster Co., 170 Mitchell Ave., South San Francisco; 650-873-9000 or newenglandlobster.net