The chef, a Martha's Vineyard native and 12th-generation islander, is standing under a low sky on a sliver of seaweed-strewn beach. “Insane in a good way.”

In one muscle-memory-honed move, he shucks, slurps, and swallows. After a pleased sigh, he tosses the shell onto the sand.

“My dad used to feed me these when I was in diapers,” he tells me. “It's like I have a Pavlovian response to them or something.”

He reaches down into the half-bushel bucket he and his father have just filled from the cold, salty waters of Menemsha Pond, grabs another clam, and readies his pocketknife.

He invites me to tag along as he pulls together a beachside dinner for friends; I readily accept.

The Vineyard is an island, about 100 square miles, off the coast of Massachusetts, and a world away from my home in muggy Manhattan. I'd never been before, but everything I'd read about the place promised a weekend of summery perfection. Produce from local farmers so trusting they leave their stands unmanned, tin cans at the ready so people can pay on the honor system. Seafood that needs nothing but olive oil and salt as seasoning. Afternoons spent splashing around in hidden ponds at the end of wooded paths. Seersucker and madras prints optional.

The perfect place, in other words, to learn a little bit about laid-back cooking and entertaining, an ideal bastion of bucolic casualness.

That was the idea, anyway.

But my first day on the island, flying solo, felt like one big exercise in hooliganism: I kept coming up against no trespassing and private signs, kept having to maneuver the car backward down sandy roads, one hand on the wheel, one hand raised in a sheepish wave. I needed a guide to the island, and Fischer, who traces his roots back to a 17th-century patriarch named Henry Luce (yes, one of those Luces), is an ideal candidate. He remembers when phone numbers on the island were only four numbers, not ten. "I went to kindergarten in a chicken coop," he likes to say. When he invites me to tag along as he pulls together a beachside dinner for friends, I readily accept.

Our first day together begins at the Chilmark General Store, which has been the center of the blink-and-you'll-miss-it town of Chilmark for more than a century. A ruggedly handsome, salt-of-the-earth kind of guy, he's wearing a ripped T-shirt and work boots, a five-o'clock shadow, and a thick layer of dirt under his fingernails. Born and raised a few miles away, he left to cook around the world—at Mario Batali's Babbo in New York City, Ruth Rodgers' River Café in London, Alice Waters' Sustainable Food Project in Rome—but returned to the island when his mother passed away, and eventually took over his grandfather's five-acre Beetlebung Farm, named after a native tree, when Poppy passed away a few years later.

This summer, after a couple of years of juggling farming duties with running the local Beach Plum Inn restaurant, he's turned his focus entirely to resurrecting the glory of Beetlebung, which has been in the family since 1961. On any given night, you might find him pulling up chive flowers here, lettuce there, improvising casual dishes to serve in the farm's greenhouse for friends and farmers who work alongside him. The beachside get-together he's throwing, he tells me, will be a little more formal, but not much.

We drive to Larsen's Fish Market, a Menemsha mainstay run by the weather-beaten, no-nonsense Betsy Larsen, who's known Fischer since he was born. The first order of business is to sit on the dock eating raw oysters and littlenecks, and watch Bob, Betsy's husband, unload that day's lobster catch a few feet from the shop's back door.

“You can see how fresh this food really is,” Fischer says, before putting in an order for fish for tomorrow.

En route to pick up some feta for a salad, we take a quick detour down a sandy road and pull up to Tea Lane Farm. Fischer wants to check on some piglets. A family friend, who rents the farmland from the Martha's Vineyard Land Bank Commission, allows Fischer's cousin, Josh Scott, to graze his cows, sheep, and pigs on her land. Fischer and I carefully step over the electrified fence to find Anya, one of Josh's two enormous black sows, conked out in the shade, snuffling her way through some porcine dream.

“Anya, where are your babies?” Fischer asks quietly, leaning down to rub her belly before gently probing to see if he can feel any piglets inside. She lets out a snort-sigh. No dice. A few yards away, the other sow guards her impossibly cute one-week-old piglets, tiny mouths turned up into wide smiles, all tottering around on tiny legs as if lacking knee joints.

Our final grocery stop is at Mermaid Farm and Dairy, producer of Fischer's favorite feta. Fischer pops into the small, unmanned hut at the front and returns with a farm-fresh coffee lassi from the fridge, depositing money in—yes!—a tin can before heading up toward the farm to drop off some angelica seeds he's brought back from a trip to Japan. Caitlin Jones, who owns the farm with her husband, is watering plants in her greenhouse while listening to a podcast on the Paleo lifestyle.

“There's so much sugar in that thing,” she says, gesturing to the lassi. “I had a sign up there that said, ‘If you want to eat a lot of sugar, that's your problem,’ with a little border collie sitting on a fighter jet. But, I don't know, it's gone now.” Her ten-year-old son, Kent, drives by on a small Kubota tractor, one arm slung over the wheel, a long piece of grass hanging out of his mouth. He and Fischer exchange nods.

A few hours later, we close out the day at Beetlebung Farm, where Fischer's love of the land started, where he and Poppy used to plant perfectly straight rows of asparagus together, to be eaten, as his grandmother preferred, cooked in butter and served on toast. Fischer shows me where this year's asparagus is, yanking up a stalk that's a few feet tall, then pulls what he calls the “paintbrush” off a nearby fennel plant, a little frond, and gives it to me. It's intensely sweet, almost saccharine, with a strong flavor of anise.

Sheep from a nearby pasture bleat to each other as the sun starts to set. Fischer's grandmother will turn 100 in two weeks and lives in a house on the farm's property where she once ran a beauty salon. I follow as Fischer heads over with a lobster he picked up from Larsen's flapping in his hand. She's set up in front of the TV watching the baseball game. As he goes to the stove, I wish her a happy birthday.

“Oh, I don't know anything about a birthday,” she demurs. I catch Fischer grin as he dunks the lobster into a pot of water.

The next day breaks overcast and cool. Fischer meets me barefoot at Alley's General Store, where he hops in my car and directs me down a back road to the house of Olivia Pattison.

“Gathering is part of the meal,” he says. “Whether grabbing things from the garden or hunting or fishing.”

Or, in this case, pie pick-upping.

Pattison is a friend who used to make desserts for him at the Beach Plum Inn. Today she's made two pies, filled with ripe blackberries and blueberries, along with a few loaves of sourdough bread she's thrown in, just 'cause. It's barely 8:30 on a Saturday morning, but Fischer strides right into her house ("I'm comfortable going into different houses, borrowing this and that—it's just how I grew up," he states, as he does just this), where she's frying up bacon for breakfast. He gives her dog a rough scratch behind the ear, then piles his baked loot into his arms and places it in the car. Then it's down yet another bumpy road to yet another friend's house, where he's planned to prep for the party. It's about a mile from there to Black Point Beach, another off-limits-unless-you-have-the-key (literally, there's a gate and a key) beach, but one that, I'm unsurprised to learn, Fischer can get onto, no problem.

His roommate pulls up a truck, and the three of us heave a wooden table into its bed, then drive to the shore and lug it down a path lined with pink beach roses that dead-ends at the dunes. “There's a lot of schlepping when you cook on the beach,” Fischer tells me, “but food always tastes better there.”

The beach is wide, deserted, abutting a reed-filled pond where, out of the corner of my eye, I catch a satiny otter slip into the water as we walk by. A little slice of Eden, right here in New England. The clouds have burned off—it looks like we'll get a nice sunset tonight.

Back at the house, we can hear the low roar of the surf as Fischer gets organized. He's learned different styles of entertaining from various mentors along the way.

“With Mario, it was all loud music, drinking, keep the party going,” he says. “Alice had great taste and was all about hospitality.”

While he can appreciate an elaborate tasting menu, his own approach is simple: “You can do all you want with ingredients, you can do all you want with technique, but you need to know your audience.”

His audience today—mostly close friends, many of whom he's known since he was a child—wants the food that earned him a name on the island and beyond: unfutzed-with flavors, casually presented.

“One of the dishes I was most proud of at the Beach Plum last year was bonito,” he remembers, as he puts some potatoes on to boil for a seafood stew, which will feature the Menemsha Pond clams we gathered earlier. “We tasted it before service, and it was such a perfect representation of the fish that we served pieces of the loin with nothing. Just slices of loin on a plate.” He starts unpacking produce and laying it out on the counter in neat piles, then adds: “The discipline, the restraint of leaving that extra stuff off? That's key.”

I watch him slice fennel bulbs slowly to yield paper-thin slivers that will be tossed with grilled corn and some of Mermaid Farm's feta cheese—white and creamy like whipped butter—and take the stems off shiitakes, which he'll serve with a simple chile marinade for snacking. His tomato salad is little more than red onions and cherry tomatoes marinated in oil and vinegar, then laid on a bed of thick-cut heirloom tomatoes with a little torn mint on top. Each thing I watch him put together, I think, Aha, of course, I can do that, too. And then: Why don't I do that all the time?

The dishes fall together seemingly at random yet make utter sense. He tosses, tastes, rips, his hands coated in oil, the motions visceral and a bit prehistoric.

He likes the idea of giving people mugs of hot soup as they gather, so, in a nod to the time he recently spent in Japan, he simmers kombu and bass in a pot to create a kind of Yankee dashi, to which he adds miso paste and scallions. He pulls together a simple marinade—just soy sauce, mirin, and honey—for fluke steaks, which he'll grill down on the beach. I feel a little pang when he throws our clams into the pot with the potatoes—I'd had a raw one down on the beach, an ice-cold shot of brine that woke me up better than an espresso. But I figure: Man tamed fire, might as well use it. Particularly if there's going to be grilled fresh bread for dunking.

We chat and prep for a couple of hours, and before I know it, it's dinnertime. No formal recipes, no timers, no real plan—the way I'd kill to be able to cook.

Down at the beach, it's somehow all come together. His friends have laid out a tablecloth, silverware has materialized, there's a cooler packed with ice-cold vinho verde, even a fire pit. Folks I've met over the past few days are there, and it seems only natural to exchange hugs.

Fischer has forgotten a ladle, so he uses a metal cup to portion out the soup, which everyone sips down, murmuring happily. Then they sit and help themselves to salads, just-off-the-grates fluke that has crisped on the edges, and heaps of clam and mussel stew.

“Chris, man, this food,” Tom Lesser, Fischer's former neighbor, manages before simply laughing and turning his attention back to the plate. As I pick the meat out of a steamed clam, it's hard to imagine the food tasting better than it does right here, on this beach, with hazy light settling over us and the surf crashing a few yards away.

Fischer sits down with his friends and eats the fluke with his hands. There's just enough time for pie before the sun sinks and the wind kicks up. And then, just as easily as it all came together, it disbands. Without being asked, as if they did this every night, each person picks up something—a bowl, a glass, a bench, a pot, a couple of folks to the table—and transports it to the parking lot, where it'll all be schlepped back home in the truck. Then everyone gets into cars and retreats through the maze of private bumpy back roads, dispersing in the dusk across the island, another Vineyard evening come to a close.

To get a behind-the-scenes look at Fischer's elegant marinated tomato and mint salad, head here.

Larsen's Fish Market
56 Basin Rd, Chilmark, MA 02535, (508) 645-2680
This family-run operation boasts some of the freshest seafood on the island. For lunch, grab a dozen shucked oysters or a hot buttered lobster roll at the take-out window and eat outside on the docks, watching as various Larsens unload the day's catch.

The Bite
29 Basin Rd, Menemsha, MA 02552, (508) 645-9239
If you love good, crispy fried seafood—and who doesn't?—head to this small take-out shack with picnic tables out back. Get there early, when the fryer first starts up and the lines are short, for a paper container stuffed with crisp, golden fried clams or shrimp.

7a Foods
1045 State Rd, Vineyard Haven, MA 02568, (508) 693-4636
Billing itself as a "farm-to-takeout" joint, this small shop sells one of the island's great breakfast sandwiches (add the bacon), along with a handful of lunch sandwiches, prepared foods, and baked goods. Most of the ingredients are sourced locally.

Lambert's Cove Inn
90 Manaquayak Rd, West Tisbury, MA 02575, (508) 693-2298 This charming inn, located on seven acres in West Tisbury, offers 15 cozy guest rooms and a 70-seat restaurant. A full cooked-to-order breakfast is included in the room price.

Captain Flanders House
440 N Rd, Chilmark, MA 02535, (508) 645-3123
Located on 60 acres in the small town of Chilmark, the main farmhouse of this inn dates to the 1700s. Fresh bread, muffins, honey, and jams are part of the complimentary breakfast.

You can reach the island by either water—ferries leave frequently from various locations on the Eastern seaboard—or air.
For more information, go to mvy.com, where you can also learn about the island's beaches, many of which are private or require parking permits.