1250 S. Hayes St., Arlington. 703-415-5000. Open: in the Restaurant, for lunch Monday through Saturday 11:30 a.m. to 2:30 p.m., for dinner daily 5:30 to 11:30 p.m., for brunch Sunday 11:30 a.m. to 2:30 p.m.; in the Grill, for lunch Monday through Saturday 11:30 a.m. to 2:30 p.m., for dinner 5:30 to 11 p.m. Closed Sunday. All major credit cards. Reservations suggested. Separate non-smoking sections. Restaurant prices: lunch appetizers $5.75 to $7.50, entrees $7 to $19.50; dinner appetizers $5.25 to $9.75, entrees $12.75 to $25.50. Grill prices: lunch appetizers $3.85 to $7.25, entrees $12.75 to $18; dinner appetizers $4.75 to $8.75, entrees $14 to $32. Full dinner with wine, tax and tip about $50 to $60 per person (in both dining rooms). Sunday brunch $30 per person plus drinks and tip.

AFTER A SURFEIT OF MODERN cooking and a frantic rush to be up-to-the-minute, people are returning to old-fashioned virtues. Is there a good onion soup left in this world? Are we too late to ever again taste a well-made beef Wellington?

Yes and no.

If you want one more chance to experience these glories of decades gone by, you can return to the past at Pentagon City's Ritz-Carlton Hotel. This new hotel's dining rooms -- one called the Restaurant and the other called the Grill -- look as if they have been immaculately buffed and polished for years. Their luxury and spaciousness shut recession out of your mind. The service is suited to an era of grace and solicitude, a time the Me Generation sadly missed.

And while much of the food has little to recommend it, there are two overriding reasons to try the Ritz-Carlton. One is Sunday brunch in the Restaurant, and the other is a 1950s-style meat-and-potatoes dinner in the Grill.

If nothing else, there is great serenity in spending a Sunday midday on a thickly upholstered curved banquette, sur- rounded by classical oil paintings in gilt frames, chandeliers with tiny pleated silk shades and displays of antique china in glass-fronted cabinets. A pianist plays show tunes in the background. A waiter pours fresh orange juice into crystal stemware. Coffee is served from a silver pot, and the buffet table is decorated not just with flowers but with antique bibelots and lace.

The main buffet is a lavish burst of three kinds of caviar with tiny blini, and smoked fish galore: smoked salmon, gravlax, smoked tuna and smoked trout. A giant silver bowl of ice holds an abundance of shrimp, along with crab claws and mussels. The platters of meats include luxurious prosciutto and hams, as well as raw-beef carpaccio strewn with parmesan and capers. Pa~te's, galantines and fish mousses shimmer under their gels. The cheeses ooze compellingly, their platters piled with walnuts to complement them. The fruits are lush. The salads of seafood and pasta taste just ordinary but look stylish, and alongside the bagels is cream cheese piped to form a cake.

Of course there are hot dishes too. The beef Wellington is good enough to remind me why I was once impressed by the dish. The beef is very flavorful and tender (though not rare enough for me), the duxelles is classic, and the crust may be a little soggy, but it is handsome. Most important, the accompanying madeira sauce is excellent. The usual hot breakfast items are abundant: thick-cut crisp bacon, mild sausage, ham, scrambled eggs cooked into soft folds and sprinkled with chives, prettily poached eggs with hollandaise and bits of tomato on fresh artichoke bottoms. Newer fashions are also competently rendered: The grilled tuna with julienned leeks and mushrooms is far better than one would expect on a steam table, and glazed baked chicken is still juicy. Even apple crepes have an old- fashioned quality, the crepes thin and well browned, the apple-almond filling quite sweet and also quite flavorful. Only the bland, soggy saute'ed potatoes are disappointing.

The pastries are jewels, glistening raspberry mirroirs, creamy layered construc- tions of white or dark chocolate, tiny cream puffs and eclairs, miniature lemon tarts piped with a crisscross of meringue. And among the danish, muffins, nut breads and coffeecakes are some of the best croissants I have tasted on this side of the Atlantic. The dessert table is a real-life re'sume' of an accomplished pastry chef.

Every time you return to the buffet you can expect your previous plate to be whisked away, your silverware replaced, your napkin refolded. And for each new foray to the pastry table, you can expect fresh coffee.

As for the rest of the week, at lunch the service has been stiff and confused, the food ordinary at best, and sometimes dreadful. Even the bread has been an embarrassment. As for the coffee, when at 2 p.m. we asked the waiter whether the coffee was fresh, he said no, a pot is brewed just once, at noon.

The dinnertime staff has been far more polished (though the bread has been no better). And the food can be good, particularly the wild mushroom soup and the charred tuna appetizer. But it is very fussy cooking -- the tuna slices are arranged into a heptagon, and the beef tenderloin special is wrapped in an herbed crepe that looks like a shroud (and tasted like a mistake). And like lunch, the dinner can show incompetence: tough and bouncy seafood timbale (a special one night), an unsightly rim of fat on each slice of duck, an overcooked and chewy tuna steak. Even the desserts, which have been glorious at brunch, were stiff and grainy at dinner.

Dinner in the Grill is another matter. This wood-paneled room -- with cloying hunting-dog paintings -- is utterly comfortable, its tables lit by small lamps and handsomely set with cobalt blue glassware and service plates with matching rims. The service is well honed, with no stiffness. Even the bread is better than in the Restaurant. While I didn't try much of the menu, the food, from the capellini with smoked chicken, cream, fresh herbs and plenty of pepper as an appetizer, to a homey and moist scrod with mustard sauce as a main dish, was agreeable. And those main dishes are ceremoniously presented under grand silver cloches.

Most important, though, the Grill serves an ideal traditional roast beef dinner. Start with onion soup -- it's been decades since I have tasted such conscientiously made and absolutely delicious onion soup. Continue with roast beef, thickly sliced, cooked exactly to specifications, perfectly trimmed and above all a superbly flavored slab of meat unsullied by any manufactured "jus." It is garnished with a fan of lacy and wildly luscious gaufrette potato slices. Add, if you will, an a la carte order of saute'ed wild mushrooms or lightly creamed spinach. And complete this traditional American-grill meal with, of course, cheesecake. The Grill serves a chocolate espresso cheesecake that Sara Lee would wish she had invented.

Dinner at the Grill finishes with a silver plate of chocolates, beautiful chocolates to end a beautiful evening circa 1955.