FOR A MAN whose professional life revolves around lobster—which, in California at least, is generally considered a high-end delicacy—it's surprising to hear the words, "I'm a Fluffaholic" come from Russell Deutsch's mouth.

But there it is.

The owner of Old Port Lobster Shack in Redwood City, who makes his living selling $18 lobster rolls and all manner of shrimp, crab and clams, is mad about marshmallow Fluff. With Fluffernutter sandwiches on the kids' menu, how can you not love this place?

Fluff aside, Old Port Lobster Shack is all about crustaceans, and though rumor of authentic, packed-to-overflowing lobster rolls is what put this place on my radar, it's another dish entirely that's keeping me up at night, drooling on my pillow. If I ever commit a heinous act of murderous violence, I'm begging for Deutsch's lobster mac and cheese ($9.75 half order/$16.75 full order) for my final meal. A Gruyère-laced béchamel cuddles pasta shells and morsels of sweet, firm lobster, creating a dish worthy of near-psychotic obsession.

On to the lobster rolls. Having spent seven years in the greater Boston area, I'm no stranger to this much-revered New England staple. And the version here is indeed authentic, with the lobster flown in directly from Maine. Keep expectations realistic, though. Just because they set you back $17.75 a pop doesn't mean there's foie gras tucked among the belly meat. No, this is a clean, pure and shockingly simple sandwich: a toasted, buttery hot dog–style bun cradles fresh, juicy lobster meat, seasoned only with salt, pepper, lemon and green onions. That's it. There's nothing flashy going on, and that's the point. Deutsch keeps out any crunch—he's not a fan of celery or lettuce on his rolls—and even the touch of mayo on the Maine version just barely slicks the meat. (There's also a "naked," mayo-less roll served with a large thimbleful of drawn, i.e., clarified, butter.) Deutsch and his wife were inspired by the rolls at Jake's Lobster Pound in Nantasket Beach, Mass., but the end result, he says, is his.

As good as the lobster rolls are (and they account for 40 percent to 45 percent of the restaurant's business), there were several other menu items that impressed me just as much. The lobster bisque, for one. Lobster bodies and diced vegetables are roasted together to form the soup's deeply flavorful base, on which beautiful, tender lobster meat perches languidly. Order a mug ($7) or a bowl ($9.75), but do order it. It's far better than the disappointing New England Clam "Chowdah" ($5.75/$8).

Fried options abound and the clean-tasting trans-fat-free oil means you can indulge your cravings for crunchy fish with less guilt than you might elsewhere. Three pieces of beer-battered haddock ($10.75) are beautifully crisp, served in a paper-lined basket with thick, steak-cut fries, tartar sauce, lemon and a refreshingly cold, sweet-tangy cole slaw. Like some of the other dishes here, it's underseasoned, but an arsenal of condiments on the table—salt, pepper, ketchup, mustard, two kinds of Tabasco and malt vinegar—allows you to doctor everything to your liking.

At $36.75, the "Lazy" Baked Stuffed Lobster might require a second mortgage, so be forewarned. The tail is left intact while the body has been stuffed ever so lightly with breadcrumbs and lobster meat. It's less of a project than cracking into a whole lobster, but it certainly satisfies.

The eatery offers wine as well as a large selection of Maine brews, including Sea Dog and Shipyard IPA. Ask for a taste of the blueberry wheat ale, which the cashier will happily tap for you. Service here is friendly and warm.

The nautical décor proudly showcases all things Maine—we're talking lobster traps, buoys, a spinning lighthouse, Portland Seadogs flags, maps and paintings of fishermen. You order at the counter and servers bring food to your picnic-style table. A roll of paper towels lies within easy reach and you can grab lobster bibs, crackers and wet-naps from the front counter.

Desserts are made in-house, though neither the blueberry bread pudding nor the gelatinous blueberry pie impressed me. If you'd like a sweet ending, order an icy-cold root beer float instead. It's a fitting finish to a casual, though admittedly pricey, meal.

I can see why Deutsch's empire is expanding so rapidly. (This Redwood City location is the first of three, with others in North Beach and Napa.) This is a place to hang out, chow down and enjoy pristine seafood in a fun, unprissy setting. Plus, there's no better place to congregate after watching a Red Sox game on TV.