WHEN I was living in New York, I once prepared a dinner for several of the Monty Python troupe on somewhat short notice (two days: ham, appropriately). But it was only residence in Washington that brought me face to face late one Sunday afternoon with the need to feed a Visiting Foreign Dignitary (plus 14 others, including a bodyguard) in four hours' time. It happened like this:

Earlier in the week a phone call from The Liaison had alerted us to the impending Washington stopover of the VFD. Would we, he implored, put together an informal evening of journalists to meet this VFD and discuss--off-the-record, of course--his country's problems? Sure, we agreed, and promptly began extending invitations. That was a Monday; the dinner was set for the following Sunday evening. It wasn't difficult to find people interested in meeting our VFD, and so on Wednesday we left Washington to attend a conference, knowing the stage was set. However, returning Friday afternoon, we got a severe shock.

In our absence the nervous Liaison, wanting to confirm everything, as people in his line of work are wont to do, got in touch with my husband's office. "They're out of town," he was told by the receptionist, and, panicking, he didn't bother to ascertain when we were coming back. He assumed the worst, and quickly made other plans for the VFD. Next we were on the phone, canceling the event that we were supposed to host. A little embarrassing--that'll teach us to get mixed up with people whose precious time other people are paid to worry about, I thought, and began to look forward to a weekend uninterrupted by extensive shopping and cooking.

Saturday passed. Then, as our peaceful Sunday reached the halfway mark, the telephone rang. Listening to my husband's end of the call, I realized that it was none other than The Liaison. Would we? Could we? Somehow, the dinner was on again, if we were softhearted enough to comply. Favors come no bigger than this, but the challenge was irresistible. Putting my husband in charge of reassembling the guests (in fact, the worst job, I felt, explaining being harder than tackling the grocery aisles and the stove), I immediately did the only thing possible at that moment: I made a list.

Actually, first I located a bag of new potatoes (about 3 pounds) sitting in the pantry and, making a fast job of scrubbing them, threw them into a large pan of water, skins and all. Waiting for them to boil, I got on with the list-making: jar of peanuts (for drinks), 4 roasting chickens, zucchini and eggplant (for ratatouille), lettuce, parsley, scallions, french bread, cheeses, purple and green grapes. And that was it. Already on hand were such items as garlic and onions, lemons, butter, canned tomatoes, vinegar and olive oil, wine, coffee and, most fortuitously, a scrumptious apple cake that had been an unexpected gift a few days before.

The potatoes were starting to bob amid the bubbles as I set up the tables, got out 14 plates, napkins, wine glasses, etc. As soon as they had cooked, I cooled them under running water and patted them in a dish towel to dry. Next I halved them (or cut them into thirds if they seemed too large) and placed them in a bowl, lightly dousing them with red wine vinegar and sprinkling on salt and freshly ground black pepper. Covering the bowl with the towel, I put it into the refrigerator, turned on the oven to await the chickens and set off for the store. It was 5 o'clock; company was coming at 8.

Returning in 45 minutes, I pulled the birds out of the bag before anything else and readied them for roasting. For me, this involves wiping the chicken off and filling the cavity with the liver, a lemon half, a couple of peeled garlic cloves and a few onion slices, a lump of butter and a clump of parsley, dried thyme, salt and pepper, maybe a piece of elderly carrot. Then I massage the skin with butter and olive oil (occasionally mixed with a dab or two of dijon mustard) and lay a large piece of foil lightly over the entire bird, removing it near the end so that browning will take place. At 400 degrees, I gauged, it would take an hour and a bit for the chickens to cook, and at whatever point they finished I could remove them and let them sit on platters (decorated at the last moment with parsley) to reach room temperature. This is a perfectly delicious way to serve roast chicken and one that would mesh wonderfully well with the cooled-off ratatouille and the slightly chilled vinegared potatoes.

Saute'ing the zucchini and the eggplant came next. With little regard for any recipe, I simply put some olive oil in a heavy pan, chopped and added garlic, onion and eggplant cubes (all peeled) and zucchini chunks (unpeeled). When all of these had reached softened goldenness, I added the canned tomatoes and some seasoning (salt, pepper, basil, thyme) and covered the pan for simmering. It was 6:45.

With the big stuff out of the way and the kitchen starting to offer tempting aromas to attest to my progress, I did the following--washed the lettuce and spun it dry, arranged the cheeses on a plate, made vinaigrette salad dressing, stuck the french bread in baskets, put the peanuts in bowls in the living room, rinsed the grapes, and added about a cupful of chopped scallions to the potatoes. At 7:30, the chickens were out (nicely browned), the ratatouille was in a large serving dish in the refrigerator along with the potatoes, and I could hastily shower and dress.

By 8 o'clock candles were lit, the wine was opened (vin rouge ordinaire, uncorked to have one more thing out of the way, not to enhance its bouquet) and 14 placecards were on the table (the nameless bodyguard ate in the living room). The potato "salad" and the ratatouille came out of the cold just as the first diners showed up at the door; plenty of time for the chill to come off them as people arrived and got to know each other over drinks.

When it was all over, and the VFD, who'd unbent considerably as the night progressed and seemed to have had a terrific time, had departed, the remaining guests, knowing a conjuring act when they'd seen one, toasted the cook. I accepted the praise, but it wasn't really magic at all. Chicken and veggies, salad and cheese, fruit and cake: it was essentially a very simple meal that had the advantage simple meals often have, and that is that they can seem elegant with almost no effort. The four hours of unremitting activity had involved efficiency, not intricacy. Most important, though, was knowing what ingredients I had and understanding how to get from those to results. It was fun to pull off such a last-minute coup, and I was grateful, all things considered, for the guest-of-honor's gratitude; for I was reminded that it wouldn't be unusual for a VFD, eating a meal prepared for 15 (including a bodyguard!) with four hours' notice, to act as if he was doing us a favor. PAT WALSH'S APPLE CAKE (Makes a 9-inch cake)

That night I had wanted to be able to take credit for the moist and light apple cake I served along with the bunches of grapes. Honesty prevailed. Here's the recipe and its proper credit. 3 cups flour 2 1/2 cups sugar 1 cup oil 4 unbeaten eggs 1 teaspoon salt 1/3 cup orange juice 1 teaspoon vanilla extract 3 teaspoons baking powder 1 cup chopped pecans 6 to 8 apples, peeled and sliced, mixed with 1/4 cup sugar and 2 tablespoons cinnamon 1/2 to 3/4 cup brown sugar for topping

Put all ingredients, except apple mixture and brown sugar, in a large bowl. Beat until well blended. Then, in greased and floured 9-inch tube pan, alternate layers of batter and layers of apples, about 3 layers of each, starting with batter and ending with apples. Sprinkle the top layer of apples with brown sugar. Bake at 350 degrees for 1 1/2 hours.