Ridgewell Caterers/A capital gain. Along with the food, you may get Superman or Little Bo Peep

It was ``hostess with the mostest'' Perle Mesta who, back in the '60s, commented, ``To attract a crowd in Washington, just hang a lamb chop in your window.'' Ridgewell Caterers does it differently. It sometimes hangs the president of the company out a helicopter window.

``Here's a picture of Jeff as Superman. He had himself lowered on a wire from a chopper at one party,'' explained Bruce Ellis, Jeff's younger (by two minutes) identical-twin brother, and vice-president of Ridgewell. ``Here's one where Jeff went to a party dressed as a bunch of purple grapes, you know, like in the Fruit-of-the-Loom ad. Jeff is a real `wacko,' '' Bruce laughed.

Certainly not your average company president. But then, Ridgewell is hardly an average catering service.

When one of its fleet of 30 magenta Mercedes diesel trucks emblazoned with golden peacocks pulls up at a local embassy, you can bet it's not there to deliver a Tupperware bowlful of California dip.

It started humbly enough. ``Grandfather [Charles Ridgewell] was a butler at the British Embassy; his wife, Margaret, was an assistant cook at the French. They started helping people with parties after the Great Depression, when the wealthy had to give up a lot of their help,'' Bruce continued.

From crackers 'n cheese for starters, Ridgewell's has grown to a $13 million-a-year cornucopia, spilling an avalanche of shrimps and chocolate truffles to as many as 7,000 members of Washington society in a given day.

As times change, so does entertaining, and part of Ridgewell's success is keeping up with the times.

``Things changed after the Kennedy era,'' Bruce explained. ``Back then most parties were large private or political affairs. Now, about 80 percent are put on by corporations. Tonight we have one for 300 at the Phillips Collection for the American Bankers Association, and at the Corcoran Gallery for 400 sponsored by the National Ocean Industries. We'll have other things going, but those are the two big ones tonight.''

Two hoity-toity parties running at the same time for 700 people? A piece of cake!

Ridgewell's caters some 9,000 affairs a year. Nothing is too lavish or little -- from a $200-a-plate, black-tie, French-service, sit-down dinner for 1,500 to a quiet picnic for two on the banks of the Potomac.

``We'll even deliver dinner on a bed tray to a new mother,'' Bruce said, adding, ``We've done parties in airplane hangars, in tents, on ships, and even one in balloons. We did a sit-down dinner for 1,400 big ones when the POWs were returned [from Vietnam], and also catered the Begin-Sadat dinner.''

Touring Ridgewell's is like going backstage at the circus. Under some 45,000 square feet of roof, you'll find carpenters pounding away, making coatracks and boxes; painters spraying rows of chairs (``We need 200 extra black chairs for a party next week,'' Bruce said); artists carving ice and Styrofoam into eagles and statues; and an international kitchen crew busy cleaning 5,000 mussels and turning out mini Beef Wellingtons by the score.

Warehouses are stacked floor to ceiling with Reed & Barton silverplate chafing dishes, coffee urns, and flatware. ``Every piece of silver is polished after one use,'' Bruce said, puffing, as we raced through. ``We have 40 gas stoves to take along with us. We set up a kitchen everywhere we go.''

Entertaining is big business in Washington. ``Parties,'' according to prominent Washington hostess Allison LaLand, ``are the grease that makes the wheels go round.'' Ms. LaLand, who also lectures on the social implications and history of entertaining, continues, ``They are often an extension of the workday here in Washington. Most take place during the week, and they tend to finish early.

``The hardest thing to get used to is that often you entertain the office here, rather than the person. I remember getting a call from Martha Mitchell after her husband, John, resigned. She asked if she could still come to my parties. I said, `Yes, of course.' ''

Still, parties are an art form, and more, Ms. LaLand says. ``They reflect the thinking and attitude of the times. Iranians were the big party-givers before the Shah lost his crown. Now embassies are less anxious to display lavish amounts of conspicuous consumption,'' she adds.

``It's interesting, too, to see people in different lights,'' says Bruce Ellis. ``Take [Ardeshir] Zahedi. He was the Iranian ambassador. Before a party he was an absolute tyrant. Everything had be perfect. When people started arriving, he was completely charming. Then when everyone went home, you'd see him spooning beluga caviar out of a No. 10 can, making caviar sandwiches for the waiters. People are very different planning, hosting, and after a party. It seems the bigger the person, the nicer they are and the less they have to prove.''

In this business of stuffing squab and serving pheasant, Jeff and Bruce have played passenger pigeon on occasion.

``One time at the Iranian Embassy, the Shah was in the middle of a speech when Soviet Ambassador [Anatoly] Dobrynin took out his pen and wrote a note right on the Belgian damask tablecloth. He asked for a pair of scissors, cut out the note, and handed it to me. I had to crawl around the tables on my hands and knees and pass the note to the Shah,'' Jeff relates. ``To this day, I have no idea what it said.''

Passenger pigeons, sometimes -- stool pigeons, never. ``We're privy to a lot of things, and are often sworn to secrecy,'' Jeff adds.

They can talk about it after the fact, however. Like knowing about the Russian grain deal, and that Walter Mondale was going to be tapped as Jimmy Carter's running mate.

Later in the day Bruce, in a natty three-piece suit, was helping drag a big brown gas stove into the basement of the Phillips Collection for the bankers' party. ``We only have a couple of hours to set up from the time the museum closes to the public,'' he groaned. ``And when the curtain goes up, we've got to be ready.''

In less than an hour the staff, who came in blue jeans, were in black-tie dress. Flowers had arrived, tables were decked with red cloths and laden with splendid fare, and the last candle was lit as the first guests arrived.

Before I could swallow my first sliver of smoked salmon, Bruce got a call from the Corcoran Gallery. The National Ocean Industries party had just started and brother Jeff had arrived dressed like Jacques Cousteau -- in full scuba outfit. ``Didn't I tell you he was `wacko'?'' said Bruce as we raced across town in his limo to see for ourselves.

Sure enough, there was Jeff in a complete wet suit, staggering around under the weight of a 40-pound air tank on his back -- probably having a better time than anyone else.

``You need a gimmick in this business,'' Jeff panted.

Jeff Ellis doesn't want to say whether Ridgewell is the largest catering service in the country. ``Maybe we're Hertz, but to stay on top, we've gotta keep thinking Avis.''

``And we've got to remember we're servants,'' Bruce added. ``That's the nature of the business.''

So if you attend one of Ridgewell's fetes, how do you tell the brothers apart? Well, if they happen to be catering for the American Lamb Council, that's Jeff skipping merrily around in the ``Little Bo Peep'' outfit. Bruce is the three-piece suit lugging in 50-pound bales of hay for the display.