Landscape-designer-to-the-stars Jay Griffith created his own stunning Malibu retreat with entertaining in mind. Here, he invites friends to a gathering by the sea with a Mediterranean menu from top L.A. chef Michael Cimarusti.

Jay Griffith is one of Los Angeles's most sought-after landscape designers, with clients like Brad Pitt and Cameron Diaz. He's also one of the most irreverent. "I mistrust any occasion for which you have to buy new clothes," he says, paraphrasing Thoreau, as guests arrive for one of the impromptu weekend parties at his Malibu, California, retreat. For these events, Griffith extends "day-of" invitations to whomever springs to mind—neighbors in Venice, where he keeps another home, friends from the entertainment world, former and current clients, and as many friends, children and pets as people feel like bringing. At a recent gathering, the group included film director Stephen Gyllenhaal and his wife, the screenwriter Naomi Foner; art collector Cecilia Dan; production designer Michael Riva and his wife, Wendy; and novelist Mona Simpson.

The Malibu property is certainly a great place for parties. Walk through the modest 1950s ranch home—its clean modernist lines punctuated by splashes of green and blue glass—and step outside, and that's when you get the view: a six-acre stretch of green grass and trees that runs straight from Griffith's living room to the cliffs that drop awayinto the ocean. In an uncanny way, the flow of the land makes it seem as though Griffith has sole title to both the ocean and the sky. "It's an old landscaping trick, borrowing vistas," he explains. Foner, one of Griffith's newest clients, is less reserved. "When I saw this view for the first time, I cried," she says.

Gyllenhaal is a bit more wary than his wife about the prospect of working with Griffith, who has a reputation for completely disregarding his clients' ideas about what they might want. "He's freaking me out—I'm a director, I like a script," Gyllenhaal says. Overhearing this, the other guests, many of whom are repeat clients, smile knowingly.

The ideal Griffith-designed landscape doesn't look designed at all. Instead, he subtly emphasizes or softens the property's natural contours, favoring native speciesover imports. A garden might have three types of plants rather than 15 or 20, for instance, in the restrained colors that are typical of his work: dark purples, oranges, greens. Griffith's basic rule is that the character of the land should never be compromised by the designer's style (or the client's wishes). And because Griffith works in an environmentally conscious way, he abhors the idea of wasting water and often uses succulents of various types; rows of silvery agaves are a signature.

Nowhere is this sensibility more clear than at his Malibu compound, which Griffith has dubbed his laboratory. "It's a chemistry set for ideas," he says. Originally three separate parcels, the property was almost completely barren and treeless when he purchased it a decade ago, except for patches of dry scrub and a few discarded car tires. Over the years, Griffith cleaned the place up and planted colonies of California sycamores, California live oaks, native sage, Queen Anne's lace and artemisia, in addition to other plants, to block out unwanted views and stress desired ones. A rough-hewn staircase made from railway ties leads down to a giant tepee that serves as Griffith's guesthouse, a recycled-concrete couch scattered with pillows, and a pair of fiberglass motel loungers from the '50s. Then, another set of steps rises up to a flat pad of grass and concrete in front of a rustic pavilion sheathed with rolls of bamboo fencing—a natural entertaining space.

Today chef Michael Cimarusti, formerly of the Water Grill—whose new Providence keeps the focus on absolutely pristine seafood—takes over for Griffith in the outdoor kitchen. "With all this space and the sort of sun-kissed life Jay has here," Cimarusti says, "I thought we should do something with a Mediterranean feel that was also reflective of what's available right now." He prepares two salads first—figs and serrano ham over lightly bitter wilted dandelion greens enlivened by a sherry vinaigrette, and gorgeous heirloom tomatoes tossed with briny white anchovies. Afterward, Cimarusti serves up thrillingly fresh spot prawns—"one of those particular delicacies I never knew of before I moved to the West Coast"—grilled simply with olive oil, salt and pepper and served with shaved garden vegetables. "Spot prawns are incredibly fragile but they're so delicious." From the oven comes a juicy, herb-stuffed roasted saddle of lamb, paired with delicately earthy chickpea-flour pancakes and tangy foil-wrapped fennel roasted on a bed of salt.

After dinner, a white pony appears atop a nearby hill. Griffith has released his stable of animals, most of them castoffs from neighbors, and they stream down onto the lawn. Among them are Tauro, the pony; another pony that answers to the name of Bambi; and William Jay Goat, who makes a mad beeline for Buffy, the Rivas' dog, and starts chasing him in circles.

As the light fades and coolness sweeps in off the ocean, Griffith lights Tiki torches and strikes up a fire in a pit. The group samples Cimarusti's cool strawberry soup with mint cream and vanilla phyllo crisps, while courting frogs call to one another from farm-supply water troughs positioned on either side of the pavilion. "Sometimes we get great blue heron," says Griffith, looking out over the property toward the cliffs. And later, as people start out on the quarter-mile hike back to the house, flashlights in hand, moon above, Gyllenhaal confides, "Okay—now I'm ready to throw out my plans and give Jay carte blanche in my backyard."

Michael Cimarusti's Providence is at 5955 Melrose Ave., Los Angeles; 323-460-4170.

Kathryn Harris's work has appeared in Travel+Leisure, Harpers & Queen, Wallpaper and the Los Angeles Times. She is currently working on a design book entitled Interior Life.