In the best Hollywood tradition, Milton Williams was the understudy who went on when the star got sick. A quarter of a century ago, he was working as a houseboy for Beverly Hills millionaire Leo Hartfield when the cook became ill the day of an important party. Two restaurants, La Rues and Romanoff's, could not cater the dinner, so Mrs. Hartfield in desperation agreed to let Williams handle it. Ta da! Guests Edward G. Robinson and Max Factor were so impressed they asked Williams to do their parties.

He quit his job as houseboy and his management studies at UCLA, and the world has been his oyster Rockefeller ever since. Williams' more recent productions have included Marisa Berenson's wedding, a 10th anniversary party for Helen Reddy and her manager-husband, Jeff Wald, and Danny Thomas' annual Christmas Day dinner (in an exotic Arabian dining room Williams designed).

Williams' biggest party to date was last summer's $400,000 blow-out for Paul McCartney and Wings at the former Harold Lloyd estate in Beverly Hills. Williams built a Mexican village, authentic down to the mariachis and ragged street urchins dispensing tacos. There was also a disco, the Nelson Riddle orchestra and three separate stages full of live entertainment—including the entire cast of The Wiz and the Los Angeles Ballet company. "I've never worked so hard," Milton says.

The 47-year-old founder of the Milton Williams Foundation for underprivileged children began as one himself. His father was already dying of cancer when Milton was born in the charity ward of Los Angeles County Hospital. His mother, who worked as a cook for 200 an hour, encouraged him to enter trade school, where he learned commercial baking. "I ran riot decorating cakes, and the ladies would always stipulate, 'I want one done by the black boy.' "

Today, Williams' full-time staff of 22 is kept busy living up to the boss' imagination—and strict standards. For a George Washington's birthday party in L.A., he flew in cherry blossoms from the capital. For the all-white motif of the Helen Reddy-Jeff Wald affair, it was a planeload of tulips from Holland. At many functions he tells the host and hostess what to wear—at their request.

"I like to flip 'em out each time," says Williams, who also caters small parties for 12 at $50 a head. "But I never want the feeling I'm taking over; I listen to what the hostess wants, then crystallize her thoughts. If somebody walks in and says 'Milton Williams did this party,' I've failed. But if someone is told it was me and says, 'I should have known,' then I've succeeded."

Williams, a bachelor, owns one house in Hollywood and another at Laguna Beach. But he seldom gets home to relax. With as many as a dozen bookings a week, Williams sometimes catches himself falling asleep in the kitchen, but he refuses to slow down. "I've had my clients 25 years," he explains, "and I'm not about to let them go someplace else."

Although he works nearly every holiday, Williams insists on throwing his own Christmas party. On Twelfth Night (Jan. 6) he roasts geese and poaches pears for family and friends. "To me, a party is good food, drink and entertainment—not putting on the dog," he says. Williams can prove it. His favorite dish is a hamburger with mayonnaise, thick red onion, lettuce, tomato, a lot of mustard—and chunky peanut butter.