Open Monday through Friday, 11:45 a.m. to 2:30 p.m.; Monday through Saturday, 6 to 11 p.m. AE, CB, D, MC, V. Reservations. Lunch main courses $5.50 to $11.50; dinner main courses $8 to $19.50; appetizers average $5, desserts average $3 to $5.

Maison Blanche is not just a restaurant, but an entertainment complex of ice skating in the winter, outdoor cafe in summer, this one with afternoon tea and music in the evenings, and plans to stay open outdoors until midnight. Beyond the gateway of fountains and plexiglass canopy is a cafeteria with self-service food and waiter-service liquor, turning into a disco at night. Upstairs from all this dining medley is the Maison Blanche itself, greeting you with valet parking in the evening, bringing a telephone to your table if a little business can't wait, flaming and carving and spooning delicacies in the hush of floral carpeting, the paneled dining room lavish with its space, with its velvet and brass and tucked silk. On each table is the luxurious understatement of a single rose the color of smoked salmon.

Maison Blanche, like the neighboring White House (for which it is named), understands the importance of image. At the entry is a table of made-for-TV glistening pastries and encrused pates ready for Technicolor film. A basket of tropical fruit perfumes the spacious anteroom. Etched glass dividers filter the dining room. On close inspection, the ornately framed Old Masters on the walls are really new and unmasterful. But the image works, especially in a space so vast as the Maison Blanche dining room, where one nearly needs binoculars to see who is poised against the tall leather banquettes in the rear.

An hors d'oeuvres cart rolls around the room, its colorful shreds of raw vegetable tempting one to begin with this assortment. Thus arrives the first culinary comeuppance. The hors d'oeuvres assortment-$4.95-would be overpriced even if the cart ran on high-test gasoline. Shredded carrots, marinated mushrooms, sardines, tuna, cucumber salad, potato salad crumbly from fatigue and green beans tasting of canned origins-not a single thrill in the lot-make one recognize that the price is for the serving process, not the content.

There's no denying that Maison Blanche is a grand production. The kitchen makes several pates a day, and six sherbets and its own pastries. Platters are garnished with fleurons and toast towers and paper frills. The menu touches base with every edible luxury: truffles (as appetizer, soup or main course garnish), foie gras (ditto), and caviar (only as appetizer, but at $22 a serving). The kitchen produces old fashioned extravaganzas such as Gala chez Le Cardinal des Mers, at $19.50 the top-priced main course, and a knockout presentation of lobster halves filled with lobster bits in cream sauce, piped with potato puree, topped with mussels, surrounded with rolled filets of sole and fried oysters, ladled with nantua sauce. But impressive as it looked, it added up to confusion, like an excessive heaping from a buffet table.

At first one might attribute ambivalence toward Maison Blanche's cuisine to culture shock; we have grown to expect straightforward food, simpler than what the grand old French kitchens once constructed. But further examination shows that the complexity too often detracts from the finished fish. Lamb chops look cunning spread with pate and wrapped in pastry, but underneath that light, flaky crust is a disappointing chop,small and tasting stewed from its enclosure. And when lamp chops are served, instead, grilled and frilled, and rilled with two sauces, it merely illustrates, through unfortunate contrast, that the egg-thickened sauces like bearnaise are quite correct, but the flour-thickened brown sauces are heavy and starchy. Dish after dish at Maison Blanche is pastry-wrapped: veal chop en croute, lamb chop Wellington, feuillete of trout, truffle soup, feuillete of mushrooms. And all show that the pastry chef has a deft hand with dough and a generous nature with butter; the puff pastries are as light and flaky as one might wish. But in one case the dough around the meat was soggy and undercooked; in another case it enclosed overcooked, overthickened filling. The attention to fine ingredients-thick, pale veal chops, sweetly fresh seafoods-is too often lost in excess.

Hesitating to criticize ambitiousness, I admit that I find unique sources of pleasure on the Maison Blanche menu. Les truffes du Perigord sur serviette are delicious hemispheres of butter-soft mousse of fresh foie gras, rolled in truffles (though the tasteless canned truffes add only texture and expense) and served in a napkin. Charming. The truffle soup, though its canned truffles and canned foie gras make a vapid mix, is a pastry mountain, a lot of show for a modest $4. The smoked slamon is impeccable, and endearingly garnished with painstakingly peeled lemon segments.

But basics are neglected. One dish after another tastes as if nobody ever sampled in the kitchen. Pates are oversalted, other dishes are underseasoned. The quenelles could pass for spoon-bread, so faint is their fish content. Blanquette de veau is merely high-quality, pale chunks of veal cooked dry and covered rather than permeated with its sauce. Loster bisque has undercurrents of delicious lobster essence, but it has been diluted to pallidness. The delights and disappointments of ambition carry through the vegetables: One day a tomato is stuffed with highly seasoned meat to accompany a main course; another day the accompanying tomato is grilled plain and unseasoned. The zucchini one day is exciting; the potato croquettes another day are heavy and sawdust-dry. Dessert crepes are stuffed with a flowing version of cheesecake filling with bits of apple. But the tarts, though improved on each of my visits, remain tough and lack flavor. Souffles are heavier than necessary. Even the crepes are chewy. The plates of cookies offered with coffee look better than they taste.

Maison Blanche comes close to being a very fine restaurant. Its wine list is extraordinary in the depth of its Bordeaux and California selections, but the wines are young; in a few years this will be a highly satisfying wine list. The dining room staff, though rough-edged at first, is by now suave and attentive; sill; the kitchen remains slow, especially at lunch. And at such prices-lunch hovering around $25 a person, dinner nearly twice that-culinary flourishes should be reinforced by memorable tastes.