Viennese pastry chefs can hardly be expected to give up their schlag, but one of the foremost, Walter Glocker, has diluted it by half with yogurt. And to those who have said nouvelle cuisine is dead, he and chef Werner Matt would reply that it has simply emigrated to Austria. Together they have published a cookbook -- so far not translated into English but with photos that communicate universally -- of revitalized Austrian dishes that look so light they fairly float.

Glocker's new strudel is paper-thin rounds of pastry layered with berries and a half yogurt/half whipped cream filling. It stands about four inches high and is so fragile that one taster suggested only a laser could cut the strudel without it disintegrating (which it would do anyway in about four minutes, said Glocker).

He and Matt have been missionaries of the light, the fresh, the new. Their pancakes have evolved from light to featherweight, their souffle's are made without flour, and their strudels are likely to be filled with a mixture of kohlrabi, carrots, zucchini and broccoli (or with brains and spinach, with lamb and cabbage, with cauliflower, asparagus or salisfy) as alternatives to the more familiar grapes, apples or cherries.

At the Vienna International Hilton, where executive chef Matt says he sells 1,500 strudels a day, the kitchen is stocked with lemon-balm from Southeast Asia and Matt is inspired by wontons to make tiny fried sacks stuffed with egg, brains and spinach. Most startlingly, there is white space on his plates, whereas the traditional Viennese main dish not only covers every centimeter of space but is piled a couple of inches high as well.

Matt and Glocker, who now runs a ski resort hotel and consults for the Vienna Hilton, were brought to the U.S. by Mumm champagnes to create a Viennese extravaganza for the New York premier of the film Amadeus, and they ducked into Washington to show their style at a dinner prepared in the kitchen of Jean-Louis' restaurant.

"It's a little bit French," Matt said of the "nouvelle cuisine Viennoise"; but like the new American cooking, it emphasizes the use of local products. And the chefs are also local. "There are no French chefs in Vienna," claimed Matt. "They are all Austrian chefs, even in French restaurants."

Matt's conversion came approximately six years ago, after he saw the cuisine of Paul Bocuse. Viennese cuisine was still entrenched in the tradition of richness and heaviness; in the old days, explained Matt, "they needed those calories." And even these days people thought they needed substance galore. "I still want more to eat, I want my sauce, and the sauce is not thick enough," Matt mimicked his yet-to-be-converted early customers. "The beginning was very hard," he sighed.

Television came to his rescue. After he did half a dozen television shows demonstrating the new-style kitchen, and created recipes for newspapers, his new cooking began to catch on. In the past few years Vienna has become more food oriented than ever, said Matt; "All the newspapers have a food writer. They fight each other."

And chefs began to attain the status of celebrities. At the same time, the status of waiters declined, since plates being now prepared and decorated in the kitchen. "Before, they were flaming and cutting," said Matt of pre-nouvelle waiters. "Now they just put the plate out."

Six years ago there were enough nouvelle cuisine chefs -- nine -- to form a club, which meets monthly so that members may cook for each other. Three years ago, when Matt and Glocker published their cookbook, "Erlesenes aus O sterreichs Ku che" (A Choice Selection from Austrian Cuisine), it sold 3,000 copies in the first three weeks and ultimately 25,000 copies, which is a lot for such a small country, he said. It was a revolutionary cookbook: "You don't find a goulash in there or a goulash soup," promised Matt.

The differences between French and Viennese nouvelle cuisine include more than an emphasis on strudel dough. "The French use more fish and butter," explained Matt. And the Viennese emphasize organ meats -- tongue, brains, heart and liver -- plus game. Furthermore, his nouvelle Viennese cuisine uses little wine.

"You have to drink the wine with the food, and if you have the wine in the food you don't feel very healthy," he suggested. The Austrians make a lot of soups, and so does he, but his "are nearly all a la minute," or cooked at the last minute, and the dumplings are considerably lighter than tradition dictated.

As one might expect in an Eastern European cookbook, his has several fruit soups -- pineapple with lemon and kirsch, raisin, melon -- and in his restaurant he is likely to flavor his fruit soups with herbs. This book includes a large selection of warm pastries, which are uncommon in French cooking except perhaps the newly fashionable tart tatin.

Do the Viennese experiment with the new mode of combining meat and fruit? "No," said Matt and Glocker in unison. "It doesn't go together." But Glocker's sensibilities are flexible enough to allow him to start making croissants in all sorts of trendy new flavors: hazelnut nougat with marzipan, chocolate-almond, bacon with saute'ed onion, spinach with cheese, broccoli with cheese.

Matt's Washington menu showed pheasant terrine in modern dress -- made with morels, foie gras, pine nuts, pistachios and an Austrian mountain mint -- though in Vienna he would have made it creamier and with more liver. He found the pheasant in Washington paler than Vienna's and with less wild taste. But he and Glocker were excited about the fine quality of American flour, which they said is much whiter than Austria's and makes superior brioche.

Matt was also impressed by American cooking -- to be more precise, Jean-Louis Palladin's. "Fantastic. Fantastic. Fantastic," Matt kept muttering as he was mesmerized by the stuffed venison and veal Palladin had executed using Matt's recipes as a starting point. While dinner conversation went on around him, Matt just concentrated on the plate, finally taking a deep breath and interrupting discussion of the Amadeus cake.

"It's fantastic, huh? It's fantastic," he said of Palladin's cooking, then used six more "fantastics." Palladin's venison had been stuffed with girolle mushrooms; Matt's veal had been larded with tiny vegetables. "He made it maybe better than we can do it," said Matt of Palladin's rendition. "They're very good here."

Clearly here was a chef secure enough to give credit elsewhere where it was due. As was Fritz Sonnerschmidt, educational department head of the Culinary Institute of America, when he stated recently that there are three major nouvelle cuisine chefs in Europe now: Anton Mosimann of the Dorchester Hotel in London, Eckart Witzigmann, Executive Chef of the Aubergine restaurant in Munich and Werner Matt.

Starting with a French base, as did the new American cuisine, this new European cuisine developed a regional character and local concepts to transform it into something individual, said Sonnerschmidt.

For all his modernizing of Viennese cooking, Matt tread lightly in one area. "I didn't touch the tafelspitz," he said of that classic Austrian boiled beef, which is as revered as the Vienna Opera, "because the tafelspitz is very good like it is."

And strudel dough will always be strudel dough. After all, to learn to make a really good strudel dough, said Glocker, "It takes the whole life." VEAL MEDALLIONS WITH LEMON BALM, TARRAGON, CHERVIL AND VEGETABLES IN SEASON (About 6 to 8 servings) 2 pounds, 4 ounces veal from tenderloin, saddle or top side Salt Freshly ground pepper 4 tablespoons (2 ounces) butter 7 ounces kohlrabi 7 ounces carrots 7 ounces broccoli 1 to 2 tablespoons veal stock 2 tablespoons (1 ounce) butter

FOR THE FINE HERBS SAUCE: 1 ounce shallots, chopped 1/3 cup light veal stock 2/3 cup whipping cream

%/3 cup dry white wine 2 tablespoons (1 ounce) cold butter, in flakes 1 tablespoon fresh chervil, minced 1 tablespoon fresh tarragon, minced 1 tablespoon lemon balm, minced Salt Freshly ground black pepper Dash lemon juice 2 tablespoons whipped cream

Cut the meat into 12 3-ounce medallions. Season with salt and pepper and fry in the butter until just faintly pink inside.

Clean and wash the vegetables, chop or pare into cubes. Saute' kohlrabi, carrots and broccoli one at a time in butter with a spoonful or two of veal stock or water just until they are barely cooked and glazed. Season with salt and pepper.

To make the fine-herbs sauce, boil the chopped shallots in veal stock until liquid is reduced by half. Add cream and reduce until the sauce attains a creamy consistency. Then add the white wine. Caution -- do not boil for any length or the sauce will clot. Put the sauce in a mixer, blend with cold butter flakes. Add the mixed herbs. Season with salt, pepper and lemon juice. Fold in whipped cream.

Arrange the medallions on plates, garnish with vegetables and dress evenly with the fine-herbs sauce.

Note: Use whatever vegetables are in season such as cauliflower, asparagus, black salsify or other vegetables. BERRIES IN STRUDEL-WAFERS (About 6 servings) 1 package studel or phyllo dough, at least three 9-by-12-inch sheets 2 tablespoons oil 9 ounces berries, plus extra for garnish (such as raspberries, strawberries or blueberries) Confectioners' sugar

FOR THE YOGURT CREAM: 6 ounces berries (such as raspberries, strawberries or blueberries) 6 ounces yogurt 2 ounces confectioners' sugar or to taste Juice of half a lemon 1 pint whipping cream

Roll out the strudel or phyllo dough and let it dry a half hour or more. Then cut out at least thirty 2 1/2-inch circles with a pastry cutter. Put them on a lightly greased baking sheet. Cover the surface thinly with oil and bake the wafers in a 350-degree oven until golden brown.

To make the yogurt cream put the berries in a mixer and stir in the yogurt, confectioners' sugar and lemon juice. Whip the cream and fold into yogurt.

Sandwich yogurt cream between wafers and sprinkle layers with the 6 ounces of berries, stacking 4 or 5 layers high for each serving.

Dust the top wafer with confectioners' sugar.

Puree the remaining 3 ounces berries in a blender, portion the mixture with a spoon onto the dessert along with some whole berries.