THE NOSE goes up, the mouth down. The eyes rotate. It's a face out of "Alien." A horrible, horrible face.

Dominique Nahmias makes it every time anyone suggests that it is easier, much more practical, really, to cook food in advance. She pales just thinking about listless langoustines, catatonic crayfish purchased weeks ahead, pre-roasted ducks hanging from hooks in restaurant kitchens like so many socks on a line.

"Mashed potatoes are the only thing I ever tried to do in advance and they were so awful I had to throw them away," says the 20-year-old Nahmias, the first woman chef in France to be awarded three (of a possible four) toques, or chef's hats, by the Guide Gault-Millau. She also has a black crown in the Guide Kleber. The mystery is that her restaurant, Olympe, still does not appear in the Bhagavadgita of restaurant guides, the Michelin.

A one-time law student with no formal training as a chef, the energetic, olive-eyed Nahmias opened the first Olympe three months, Gault-Millau had awarded her a toque. The Michelin did not even list it. The real reason, gourmets partial to the place gripped, is that the restaurant had only one toilet. The fastidious Michelin includes only restaurants that have separate toilets for Monsieur and Madame. So last year Nahmias moved to more elegant, roomier quarters in Rue Nicolas Charlet, farther out on the Left Bank. The New Olympe has a spacious, white-tiled kitchen -- and a bathroom for each sex.

8:15 p.m.: Aside from a white plastic bucket of water in which artichoke hearts bob with lemons, to keep them from turning brown, nothing is ready. The customers are beginning to arrive. The chef? "Gone to take her bath."

8:25 p.m.: The scent of lilacs fills the room. Nahmias has arrived. In white, as usual. Red and white if you count the Milky Way of polka dots scattered across the flowing white skirt, the scarlet stripes ringing her white socks. Deftly she folds an apron over her antique-lace blouse. Recently, a photographer from New York magazine spent an hour just photographing her white high heels. "Up close," she says, amazed. "He was crawling on the kitchen floor."

Five minutes in the kitchen with Nahmias, whose enthusiasm for food is as infectious as her directness and warmth, and there's no doubt about who's doing the cooking. "Two artichoke salads, one salmon, crayfish, one pigeon, one kidney, one duck," the waiter shouts through the serving hole. In a split second, the artichoke hearts are on to boil, the admirably active green-black crayfish -- her trademark -- sizzling in a copper pot. "Get the pigeon on," she orders her staff of six. "Cava le rognon? No water in the crayfish. It dilutes the taste." Rapidly chopping mint for the salmon en papil-lotte, she tells how she ran out of crayfish last week and phoned a restaurant that had received 30 kilos to ask if they could sell her some. "They said they had cooked all 30 kilos for the week. Imagine! For the week! It was a three-star restaurant, too!" Nose up, mouth down, eyes orbiting, she makes the face. A horrible, horrible face.

Into another pan goes a heaping whiskful of butter, saffron, lemon. She turns up the flame. "High fire. That's the secret. But people are always afraid sauces will turn. They think butter and cream shouldn't boil. All these crazy ideas. Look It's boiling now. It hasn't turned."

Besides cooking until 1 a.m. at Olympe, she gives cooking tips on television and radio and is writing a book that includes her listeners' best recipes as well as her own. Most recipes submitted, unfortunately, are what she calls "false, easy cuisine" -- with such innocuous ingredients as canned tomato paste and "bechamel." Her disdain is palpable. She encourages the use of vegetables in season and gets letters from market people, she says, thanking her for telling women to buy endives, not strawberries, in December.

Nahmias' husband, Albert, who buys the food and mans the dining room, ambles into the kitchen with the news that Valerie-Anne, daughter of President Valery Giscard d'Estaing, has just walked in. "A woman says she saw you on television," he adds.

She attributes her eclectic tastes -- ginger, fresh coriander, mint and saffron are among the many herbs and spices she uses that are rarely found in orthodox French cuisine -- not to faddy nouvellisme but to influences in her village in the Var region of southern France. Her specialities include sweet-and-sour smoked duck, langoustines with pasta, a three-course menu of daurade that begins with petal-thin slices of the raw fish with vinaigrette and carpaccio, thin sliced raw beef her Italian grandmother used to make. "I was eating carpaccio one day and a customer said, 'Why don't you make that for us?' I had never put it on the menu because I didn't think anyone would like it but me."

She whips a lemon sauce for the kidney into a creamy froth. "Ca va le rognon? How about the pigeon? Check on the duck." The duck is ready. "See how easy it is to make things to order?" Mmm. "Take a bite," Mmmmmm. "You can't compare that to something cooked ahead." Agree with you on that. "A duck takes 20 minutes! Why cook it in advance?" Who? Me? Wouldn't think of it. I'm convinced. CAPTION:

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