White Flint Mall, Rockville. 881-3360. Open for lunch Monday through Saturday, 11:30 a.m. to 3:30 p.m. Open for dinner Tuesday through Sunday, 5 to 10 p.m. Buffet Tuesday, Wednesday, Thursday and Sunday evenings. All major credit cards. Reservations. Prices: Dinner main courses $4 to $7.50.Buffet, including movie ticket and popcorn, $6.50, plus tax and tip.

You can't afford not to eat out, at least if you are going to the movies at White Flint. What's more, I don't know how the Intermission restaurant can afford to feed you (or how long they can keep it up), but along with a movie ticket (worth $3.50 to $4 at White Flint's five theaters) and a box of popcorn (worth 65 cents), they offer a buffet including salad bar, pasta, two meat or fish dishes, a glass of wine and dessert for $6.50.

First, you should know what Intermission is not. It is not a prepackaged, factory-made, unwrap-and-serve food operation. It is not a you're-paying-for-the-food-not-the-service-so-expect-none restaurant. In fact, if you take advantage of Intermission's movie-buffet combination you don't get what you pay for, you get more.

That is not immediately apparent, since the weak point of the system is the welcome. Twice I had to find a host or hostess and exercise patience while they adjusted to the fact that I wanted to eat at their restaurant and then found me a table to do so. Otherwise, the people who served dinner spent considerable energy looking for ways to make our evening comfortable.

And Intermission is comfortable. Since it turns into a disco late Friday and Saturday evenings, it wears a slick disco look, but with a certain wit. The best of the setting is that the chairs are deep and soft, and roll easily so that getting in and out to revisit the buffet table is no chore. The worst of the setting was one Sunday evening's unkemptness, as if the cleanup crew still had not recovered from Saturday night.

The buffet, as those things go, was also worn out. The salad bar, too, looked like the morning after, its bean sprouts turning brown, its lettuce nearly depleted. It had an adequate selection of chick peas, cherry tomatoes, onions, three-bean salad, bacon that tasted canned, beets and croutons. But its dressings were sharp and commercial tasting, a choice of creamy pink, creamy orange two flavors of creamy white. The rest of the buffet, however, proved better than its beginnings.

Next to the salad bar were three main dishes and a vegetable. One day the pasta was big pillows of gnocchi stuffed with a well-spiced tomato and meat paste. It reinforced the restaurant's earlier advertisements that it had the kitchen staff of the Positano (which parts of the staff it didn't specify); this was clearly similar to Positano's stuffed gnocchi, though not so refined a version as owner Angela Traettino's had been. A second dish was chicken with onions and peppers, legs and thighs swimming in an oily broth, tasting considerably fresher and more lively than it looked. There was fried perch in a light batter, buttery and once good, but overcooked by the time we rescued it from the steam table. The vegetable melange showed equally proud origins, but we had not rescued it in time. In all, it was rather good food - or could have been if we had eaten earlier, if the heat had been lower under the chafing dishes or the dishes had presented smaller portions and been refilled more frequently. Other days' choices - veal francese, sausage parmesan and manicotti, for instance - sounded even better. These are the same dishes as on the a la carte menu ( $4 to $6 for pastas, $6 to $7.50 for main courses), just the worse for wear on the buffet table. Lunch prices, as expected, are lower, and the grapevine is spreading compliments for the $2.95 hamburger platter.

Bread is a highlight at Intermission, rough, crusty, fat Italian loaves. And the glass of wine that comes with the buffet is no worse than Washington's usual house wines. For dessert you could get lucky with profiteroles or make do with too-sweet, too-heavy caramel custard, depending on the day. In any case, there are usually very good strawberries, one day with aero-fluff whipped topping, another day with real whipped cream.

The popcorn and the movie were just fair.

But there is another face to Intermission. It is a reasonably priced Italian restaurant with some very good dishes among the undistinguished ones, all of them enhanced by the environmental pizzazz and endearing service. To start with appetizers, you would not exactly go wrong with the fried mozzarella with anchovies or the fried eggplant, but even in summer you would be doing yourself a favor to order a soup. The escarole and bean soup is the kind that put Italian mothers on the map. Pastas are fine. Not great, mind you, but nice food.The pizza, however, is a brown spongy base with thick, red, acid sauce and, in our case, burned cheese; a child was heard describing it accurately as "that pizza kind of stuff." Main courses are mostly veal, though you can get commendable garlicky scampi. The specialty - also familiar if you have eaten at the old Positano - is veal and chicken scallops stuffed with sausage and vegetables in champagne sauce. It sounds great. It tastes good. Veal has been found to be overcooked and dried out, and sauces are competent but not high art. Probably the best dish on the menu is the chicken scallopine - simple, carefully prepared, buttery and lightly touched with lemon. Vegetables - usually peas with onions - are flavorful but overcooked. Instead you can have linguine with a pungent tomato sauce.

The menu is not comprehensive, nor is the wine list. But both are adequate, reasonably priced, decent, and served with solicitude. Whatever its faults, Intermission serves good value. And as long as the movie-and-buffet arrangement continues, it is an unbeatable bargain.