Foreign Fare . . . Without Airfare Lunch In Philadelphia Can Be A Real Trip And The Tariff A Bargain.

When my appetite gets a case of wanderlust, it is easy to embark on a round-trip lunch to an exotic land without ever leaving the confines of Philadelphia. And to do so cheaply is one of the greatest joys of living in a metropolis rich with international diversity.

It might be the day, for example, to visit Vietnam, to plunge into a steaming wide bowl of its mysterious soup. Or perhaps, the Middle Eastern chickpea crunch of fried falafel balls is calling out my name from inside the rolled tube of pita bread. I get a regular longing for the simple comfort of Indian curried lentils, to ladle them over a mound of fragrant basmati rice and feel virtuously vegetarian. But when I want to defy the winter cold and sate my inner carnivore, I hunker down over the glowing coals of a hibachi grill and lean into the sizzling smoke of spicy Korean barbecue.

Such destinations and their regional permutations are seemingly endless. The thrilling adventure of new discoveries is intoxicating. But where to begin?

These urges rarely find their best outlet in a gourmet setting. The trappings simply get in the way, not to mention drain my wallet. But to those restaurants that bring home authentic flavors with often outrageous value I would happily return again and again. Never mind the frequently utilitarian dining rooms, where ambience could be described as ``full frontal formica.''

PHO 75 There is something to be said for the limited menu at Pho 75, the spacious and bustling Vietnamese dining hall off Washington Avenue where as many as 500 customers a day come to choose between soup, soup, soup and soup.

After all, ``Pho'' means soup (``75'' commemorates the year Vietnam fell to the communists). And considering that much of the largely Vietnamese clientele is taking a breather from the giant Wing Phat supermarket next door, where a seemingly endless selection of dried fungi, fish sauce, Asian dumplings and produce is available, such brevity of choices must be a relief.

At $5.45 for a giant, heaping, exotic bowl of beef or chicken broth filled with a nest of noodles and sundry meats, it is also a nourishing bargain.

Soup is an all-day ritual in Vietnam, where it is not uncommon to indulge for breakfast, lunch or dinner, says Dao Pham, whose family owns this seven-restaurant chain based in the Washington area, with another local outlet on Adams Avenue in Northeast Philadelphia.