Last year there were none, and now there are three Persian restaurants, each starting from the same culinary base but presenting it to Washington very differently. As one Iranian observer of this restaurant phenomenon put it, the Caspian Tea Room, reviewed this week, is aristocratic. It aims to present a cultural experience to Americans, a showcase of the exotic in a sort of educational exchange. Our observer continued that another restaurant, Omar Khayyam, which will be reviewed next week, represents the middle class, the merchant class, adjusting Persian food to what it perceives as American tastes. And then there is the Stop Inn, typical of an Iranian student-and-working-class restaurant. It's audience is Persian; not only doesn't it aim at American tastes, it doesn't know American tastes. The Stop Inn is not trying to develop an audience; it merely fills the need of a small expatriate audience that already exists. It is where my Iranian social commentator goes when he feels homesick, perhaps not only for his homeland but for his student days as well. This week and next we will look at these three restaurants in the Persian mode.

Open for breakfast Monday through Saturday 8:30 a.m. to 10:30 a.m., lunch until 3 p.m., dinner 6 p.m. to 9:15 p.m., Sunday buffet 5 p.m. to 8 p.m. AE, MC, V. Reservations. Prices: At lunch appetizers $2 to $2.50, sandwiches and main dishes $3 to $8; at dinner appetizers $2.50 to $5.25, main dishes about $10. Sunday cold buffet dinner $10 including wine.

Politics change, but the need for food remains constant. Thus when an Iranian diplomat found himself in Washington without a job, he and his wife furnished a restaurant with their household treasures, and she set out to turn her entertaining expertise to profit. So now Washington has the Caspian Tea Room.

There is an embassy-elegant air to this shopping-center tea room. The front is clearly commercial, with a pastry case displaying a sumptuous selection of tarts and cakes grandly decorated, but in the back is a showroom of antiques even more sumptuous, gilded and inlaid and draped with velvets. In between is a dining area reflected in gilded pier mirrors and lined with flowered rose wallpaper. Rose tablecloths overlay tan ones; vases of baby carnations top the tables. Soft classical music plays in the background. It indeed looks and sounds like an Old World tea room.

The service is less polished than the furniture, with sometimes long waits for food and occasional confusion over who gets what. There is an air of cultured and absent-minded aristocracy, of otherwise-educated servers learning a new job. A little patience reaps a good deal of graciousness, however.

And the food is often worth the wait.

The menu has changed several times since the restaurant opened last winter, but seems to be settling into solidly Persian dishes with pan-European accents. Soups range from onion gratinee to borscht, salads from mast-khayar to nicoise, main courses from red snapper meuniere to veal Louisiana to fessenjan. And dinner, unless you have unheard-of willpower, ends with some of France's finest pastry inventions.

While desserts are largely and excellenty French, on my several visits I found the European dishes ranging from dull to fine, but the Iranian dishes invariably delicious. Compare onion soup -- salty and insipid one day and much richer and denser another day -- with sauteed eggplant under a blanket of yogurt decorated with a crosshatching of mint, and you'll be pointed in the right direction. I have had a pleasant creamy fish soup and a good hot cabbage borscht, but neither could compare with cold spinach mixed with yogurt and garlic that was an inspired combination and balance.

Some of the Western main dishes, particularly at lunch, are clearly misguided. The chef salad was a dull melange of paper-thin deli meats and lettuce, the croque monsieur just a greasy grilled cheese sandwich with a thin layer of deli ham and cheese. Eggs have been very well handled, from just-runny eggs benedict in a lemony hollandaise on crisp English muffin to a nicely done, softly layered omelet. At dinner, fish are good choices among the Western dishes, being well prepared, sometimes in buttery and winey sauces that manage never to be heavy. The menu has been pared from one far too ambitious to a photocopied scrawl of perhaps four seafoods, a few veal scallops, maybe a pepper steak and several Iranian dishes.

The kebabs can be outstanding, such as boneless and very tender chicken cooked to a crusty surface yet very moist, only lightly perfumed with spices. Whole Meat Kebab tastes of no seasoning at all, but is the Iranian version of a paillard, a thin slice of beef quickly cooked on a grill. Minced Meat Kebab is seasoned with onion and packed around a skewer, then also grilled to crustiness. Fessenjan was added to the menu too late for me to try it, but this chicken-pomegranate dish is one of the great legacies of the Persian empire.

Yet at the Caspian Tea Room the rice is the star.Soft and steamy rice is accompanied by butter to moisten it, tiny bowls of tangy, spicy ground sumac to sprinkle over it and a tiny cup with a raw egg yolk to work into the mixture while the rice is steamy enough to cook it to a custardy texture. The result is a mass of creamy, buttery and spicy-tart rice that is unforgettable.

Now the Caspian Tea Room is also experimenting with Sunday buffets: for summertime, a cold one from 5 to 8 p.m., at $10 a person, including a single-glass bottle of Inglenook wine.

The buffet table is set with heavy silver trays on a white lace cloth. A large flower arrangement is at one end, and each tray of food is lavished with bunches of glazed grapes, bouquets of vegetables, beds of greenery. French bread is displayed in baskets. A watermelon is carved and filled with melon wedges. Again the look is embassy row rather than shopping mall.

As for the quality of the food, one Sunday it ranged from an utterly delicious salad of potatoes with fennel-spiked sausage, red onion, capers and radishes in vinaigrette, to watery slices of what tasted and looked like pressed turkey. While nothing seemed Persian, there was a lot to like: hard-cooked eggs piped with mayonnaise and garnished with bits of roast beef, good pastrami, cold poached fish in a remoulade sauce, a spicy country-style pate layered with browned onions and a pink and creamy beet-apple salad. Some dishes needed improvement; the turkey, the roast beef, the rolled herring in tomato sauce and the over-gelatinous liver mousse were far more decorative than delicious. But three handsome and high-quality cheeses, plus a cornucopia of melons, grapes and berries, rounded out the selection satisfactorily.

To dessert or not to dessert becomes a difficult question at the Caspian Tea Room, even after a full buffet. Theirs are beautiful pastries, and among them are strawberry napoleons with fine flaky puff pastry, butter cream tarts truly with the taste of butter, creamy mousses in thin chocolate shells and bavarian creams glazed with tart apricot. A little heaviness here and there doesn't interfere much with their dazzle, although the wedges of fruit tarts are a giant step below the other pastries.

Our solution to the decision has been to order pastries to go or to take the restaurant up on its name and return for tea -- in either case, certainly to return to the Caspian Tea Room.

Next week: More on Washington's new Persian restaurants.