A killer New England clambake is a sight to behold.

Or so I’m told. I’ve never seen one. Maybe I need cooler friends, but it might also be that an old-fashioned clambake — dig a big hole on the beach, line it with rocks, light a fire, then toss in some seaweed and shellfish — is increasingly hard to pull off.

For one thing, flaming pits on public lands are generally frowned upon these days. If I saw a giant hole spitting fire on Wollaston Beach as I drove home from work, I’d assume end times were upon us and/or call the police. And even without accounting for bail money, the whole to-do is a major investment of cash and time.

So when my mother suggested having a classic New England clambake during our vacation at a New Hampshire lake house — her way of buying her way out of her night to make dinner — I was a little nervous.

Getting a caterer to come to middle-of-nowhere New Hampshire to cater a meal for nine people is crazy business; driving half an hour to get a cooked dinner, then driving back, setting up, and eating several hundred dollars worth of cold takeout is even crazier; and taking all those people and two infants out to dinner is the kind of plan that you find scrawled on the walls of an asylum.

No, I was going to have to do this myself: a classic clambake, minus the beach.

“I know the pain,’’ said Jeremy Sewall, chef-owner of Row 34 in Portsmouth and Boston, as well as Island Creek Oyster Bar and Brookline’s soon-to-close Lineage. “My family, when I cook for them in the summer, expects me to pull off miracles. I just want a day off and to grill a hot dog.

“We’ll see if we can figure this out together.’’

I’d already scoured the Internet for inspiration, finding all manner of stovetop lobster boils involving steamer pots the size of Volkswagens. But that wasn’t quite right. The broad strokes of my plan, which Sewall endorsed, included a steel tub, a raging fire, and a whole mess of seaweed.

The steel tub was easy enough — any hardware store will have them in varying sizes (I went with a 13-gallon model for about $20).

But while the simplest ingredient in a classic New England clambake is the seaweed — wade out into the ocean with your buddies and bring back a few armfuls — that gets a little tricky at a lake a good 90 minutes from the ocean. Lily pads and algae from the lake seemed like a bad idea, so I called Burke’s Seafood, an excellent little market and restaurant in Quincy. The next day, I had a trash bag full of 20 pounds of seaweed. I packed it in a cooler with ice to keep it fresh for a couple of days and headed for New Hampshire.

On the day of the cook, we picked up 10 lobsters and 8 pounds of clams to go along with the corn, potatoes, and sausage I’d brought from home.

We asked the woman behind the counter at Tides Fish Market in Rochester what size lobsters we ought to buy for our backyard wash-tub clambake.

“I don’t recommend doing that,’’ she said.

I explained that I was kind of locked into the idea, what with the photographer coming and all.

She sighed.

“Get 1½ pounders then. They’ll look better.’’

This was discouraging. But it quickly became obvious that the real challenge for this kind of clambake isn’t the fixings — it’s the fire.

“You need enough heat,’’ Sewall had told me. “Enough coals, and a really solid foundation.’’

To achieve this, we widened and dug out the fire pit so that it could accommodate a roaring fire and still handle a steel tub full of food about 3 feet across. An outdoorsy uncle got a huge fire going in the pit, and added about a half-dozen football-size rocks to the flames.

As the flames subsided, I added two full bags of hardwood charcoal on top. The fire was now too hot to stand near. We had buckets full of water lined up in case the wind off the lake sent sparks into the pine needles all over the ground and the garage nearby.

It was time to cook.

Following Sewall’s plan, we filled the bottom of the tub with salted water and white wine, then dug the rocks out of the fire with a shovel. Into the water they went, sending up a huge amount of steam. Half the seaweed went in next, then the lobsters, clams, sausage, corn, and potatoes. Quartered onions, halved lemons, and handfuls of fresh thyme came next, along with a pound of chopped butter. The rest of the seaweed covered the top, and a layer of soaking-wet burlap went over that.

We hoisted the whole thing onto the hot coals, and banked a third bag of coals — already hot — around the sides, along with more wood. Within minutes, the tub was boiling audibly, steam pouring from the places where the burlap wasn’t tucked into the seaweed.

So now what?

“You’re going to need to dig down in there,’’ Sewall had said. “If you do hard-shell clams — top necks or cherrystones — those will open in about the same amount of time your lobsters will cook.’’

We had pretty good-size littlenecks, and when I reached into the tub with a heatproof glove after about 30 minutes, the clams were wide open.

Everything had come off without a hitch until now. But suddenly we realized we had a giant, scalding-hot 60 pound steel tub sitting on a raging fire, and a single pair of overmatched heat gloves to handle it with. As the food continued to cook, I remembered Sewall’s worst-case-scenario advice:

What do you do if things really go sideways, and you end up with a dozen brutally overcooked lobsters at the bottom of a bucket?

“Make sure you’ve got a lot of beer,’’ Sewall said.

But my uncle sprinted into the garage we had somehow not burned down and emerged with a metal broomstick. We ran it through the tub’s handles, hoisted it off the fire, and carried it over to the picnic tables, where bowls of melted butter waited.

We unearthed the vegetables and shellfish and spread them over the paper-covered tables.

The first bite of lobster tail was succulent and seasoned by the beautiful, buttery broth that now filled the bucket. The corn was crisp. The clams were tender. Even the sausage was plump and juicy.

And there wasn’t a grain of sand to be found.

Nestor Ramos can be reached at nestor.ramos@globe.com. Follow him on Twitter @NestorARamos.