This is the closest Washington comes to a hyphenated restaurant, in this case American- Oriental: It is New American with an Asian twist. The delicious spring rolls and egg rolls, for instance, are lightened versions, their fillings nearly a mousse. And the wonderful fried wontons are filled with a highly seasoned ozing cheese and accompanied by guacamole. Cold chicken with red oil sauce is only reminiscent of oriental cold chicken appetizers, but very good. And the p.at,e, the most French of the appetizers, has a particular zest -- a Szechuan influence?

The main dishes, too, include such oriental possibilities as stir-fried chicken, Szechuan shrimp and vegetable curry, contrasted with purely occidental breast of duck with cassis, liver with marsala and sage, eggplant parmesan and a kind of chicken divan in a puff pastry. There is also a page of pastas, very reasonably priced around $7, and ranging from Szechuan to traditional European versions like mussels provencal and squid with red wine sauce.

In general the cooking is very good, particularly noticeable with the pastry-wrapped chicken, which could be so easily flawed. And the whole wheat bread is not only homemade but outstandingly good. In fact, the baking, from the bread to the fruit tarts, is fine here. Oddly, though, Helen's can miss spectacularly; an avocado terrine with smoked salmon was so dense and rubbery that it didn't even seem like food.

Still, the level remains high and the simple brick-walled room with big windows and arches is soothingly attractive. Service is strong on charm if less so on efficiency. The short wine list suits the food and your budget well. Helen's adds up to a refreshing restaurant where a special evening extracts only moderate cost. 1805 18th St. NW. 483-1813. D $6.95-$13.95. D daily. AE, C, MC, V. Res sugg. Full bar.