The Canonical Version

• Although lobster is considered an upscale ingredient in most of the country, it's a blue-collar indulgence in areas where it's fished. The canonical version of lobster rolls reflects this in its unpretentious simplicity. The basic version uses a split-top "New England-style" hot dog bun, usually toasted, for its roll. The split top is opened up, and the cook spoons in a generous portion of diced lobster meat. Stands that hand-pick their own lobsters usually use only the easily harvested tail, claw and knuckle meat. Those that buy mechanically separated lobster also have smaller shreds from the body and tiny swimming legs. The lobster is either warm in butter or cold in mayonnaise, depending on the vendor's preference.

Commercial Fillers

• Any ingredient beyond the lobster meat itself is hotly debated by locals and seafood purists, up to and including the mayonnaise. However, offering a lobster roll at a reasonable price sometimes means compromises, even in areas where lobster is relatively inexpensive. It's not uncommon to find roadside stands stretching their lobster by filling the bun first with a bed of shredded iceberg lettuce. Some incorporate lettuce and finely sliced celery with the lobster, making a sort of lobster salad to fill the bun. These additions aren't canonical, but they're widely accepted -- and some diners appreciate the moisture and textural contrast they add.

At Home

• If you're planning an evening of lobster rolls at home, use similar tactics to keep them from breaking your budget. In chef's terms, lobster averages about a 25 percent yield. That means a one-pound lobster provides roughly a quarter-pound of flesh for your lobster rolls. That will generously fill two split-top hot dog buns -- or three or four if you use a bed of shredded iceberg lettuce. At home, you also have the option of stretching your genuine lobster with lobster-flavored surimi, made of fish. That's a cheat, but it certainly makes the lobster go further.

Upscale Variations

• Inventive chefs up and down the Eastern Seaboard have created variations on the theme that can be replicated by dedicated home cooks. One easy variation is to use a high-end bun. Many bakeries will bake brioche into the requested shape, or you may bake your own soft buns. Flavor the mayonnaise with exotic ingredients, such as saffron or a few drops of white truffle oil, to simulate the aioli served with lobster in fine restaurants. For an especially festive touch, serve lobster rolls with champagne. Its crisp acidity makes a perfect foil for the rich lobster and mayonnaise.