TRADITIONAL MOM and Pop grocery stores are disappearing from the American urban scene, but look around any large metropolitan area and you may find a "born again" version of the old family-run operation. The ambiance is foreign, the aromas East of Suez, and Mom may be wearing a sari instead of a dress and apron. Smells of coriander and cumin waft into the street from open doors. You are about to enter an Indian grocery store.

The Washington area has several such stores, tucked away in tiny suburban shopping centers and urban store-fronts. They are usually owner-operated, and the pace is casual and unhurried. Plan for a leisurely visit and don't be afraid to ask questions.

As you step in you will be assailed by the redolence of Indian spices and attracted by the mix of colors from plastic bags of red, brown and ochre powders, jars of pale-gold homemade ghee (clarified butter), canned mangoes and lichees, bottled Indian pickles (no relation to Kosher dills), Brooke Bond teas, fresh fruit, vegetables and the fragrant green coriander, also known as cilantro or Chinese parsley. Used as a garnish in numerous Indian food preparations, fresh coriander imparts a distinctive flavor when chopped and sprinkled over soups, stews or lentils. It can also be ground into a paste and used in certain curried dishes or made into a pungent chutney. Flown in weekly from California or Florida where it is grown, it is sold in bunches by weight. Indians will travel miles to get some fresh dhania , as it is called, and consider it an essential part of their cuisine.

Spices essential to Indian cookery include ground coriander seeds, cumin, turmeric, red pepper (cayenne), cloves, cinnamon, cardamom and a mixture called garam masala , similar in flavor to ground allspice. Bay leaves, pepper corns, black mustard seeds, onion seeds, whole dry red peppers, fenugreek, asafoetida, fennel seeds and dried "curry patha" or curry leaves are often seasoned in hot oil and added to certain preparations as a finishing touch.

More exotic flavorings such as the fragrant essence of "kewra," made from the edible blossoms of the Pandanus odoratissimus plant, rose water and the very expensive Spanish saffron are generally used on festive occasions. Saffron, which sells for about $50 an ounce, is available in small jars containing a few strands and ranging in price from $2.99 to $3.99 depending on weight. Native to Spain but also cultivated in India's Kashmir Valley, saffron is used in many Indian sweets and the rich rice and meat dish known as birlyani .

Lentils, which form a basic part of the Indian vegetarian diet, can be found in six or seven varieties and are a good alternative to meat in this period of inflationary food costs. They can be cooked into dhal , a thick broth seasoned with fried onions, bits of garlic and ginger, and served over hot cooked rice. Add some vegetables, yogurt and a little melted butter and this makes a satisfying meal. Lentils can also be combined with cubed meat or ground beef into a curried dish or with assorted vegetables such as cauliflower, eggplant, carrots, beans and potatoes and a few spices to make a tasty stew.

Ask for masoor dhal , orange-pink in color and with small round grains, or moong dhal , pale yellow oblong grains. Both come in two-pound packages and sell for around $1.30 a package. A cup of lentils boiled with three to four cups of water goes a long way.

Mediterranean or pita bread has grown in popularity as a bread substitute in recent years and Indian stores sell them in 2 1/2-pound bags in the freezer section. These are large and oval shaped, soft and chewy and considerably tastier than the supermarket variety. They taste delicious when heated in an oven. Seal in foil and place in a 450-degree oven for about 15 minutes, then rub a little butter on each one, rewrap and keep warm. Known as Nan roti in India, they are wonderful for mopping up hot stew dishes or lentils in place of rice. They make hearty gourmet sandwiches when filled with spicy ground meat kawabs , a garnish of chopped onion and tomato, and a squeeze of lime; and a nice base for pizza or vegetarian pizza with a mixture of vegetables and melted cheese.

Indian pickles, not for those with timid taste buds, can be addictive. They usually come in lime, mango or mixed varieties and are heavily spiced and marinated in oil. Sweet chutneys, made of shredded mangoes, raisins, sugar and some spices are less pungent but nicely complement a hot curry and rice meal. For the more potent pickles mangoes, limes, etc. are salted and sun-dried, then cooked in oil, vinegar and a thick paste of spices before being bottled or canned. They keep indefinitely and do not need to be refrigerated. b

Ask for stuffed red peppers, whole dry red chiles stuffed with a spicy paste and marinated in mustard oil. Or "Pachranga Achar" which has five main ingredients--mangoes, limes, green chiles, lotus stem sections and ginger slices. Both come in 1 1/2-pound cans and cost around $2.25. Remember, this will probably last you for years, or arrange to share a can or jar of pickles with a friend.

In fact, cost-sharing can be an effective way of saving money when buying in bulk in this type of store. A 25-pound national brand bag of rice sells for around $10.95, much lower per pound than in a regular grocery store. Other long-grain rice sells for even less. Indian or Pakistani basmati rice, which has a distinctive, nutty aroma and is usually served on special occasions, sells for around 79 cents a pound.

For those who would like to make their own chapatis (Indian version of tortillas) or puris (fried bread), Canadian wheat flour is available in five-, 10-, or 25-pound bags for around 36 cents a pound. This wheat is soft and pliable and kneads easily. Ready-made chapatis are also sold in packages of a dozen for a dollar.

Among fresh produce available daily are good quality garlic and ginger root, okra, white pumpkin, hot green chilis and mangoes from Florida.

Indian bottled fruit drinks provide a refreshing alternative to soda or iced tea on a hot summer day and these include mango juice, orange squash, "Rooh Afza," fabled as an exhilarating drink, and rose syrup which tastes delectable when combined with ice cold milk.

A sampling of Indian grocery stores in the Washington area:

India Sub-Continental Store, probably the best in terms of variety and selection of canned foods, pickles, spices and fresh produce, is housed in a charming old two-story with wood floors and an arched doorway not far from Silver Spring's downtown area. Of the three rooms at ground level one is devoted entirely to saris, records, tapes and cassettes of Indian music, and the other two to a wide variety of ground and whole spices, dhals , rice, chickpea and rice flours, canned Indian vegetables and fruits, pickles, curry and vindaloo pastes, fresh garlic, ginger, okra, white pumpkin and bitter gourds. The store also has gleaming stainless steel utensils. It often has sales on rice, lentils, almonds and other items, sends out mail orders, posts notices of Indian cultural and religious events and buzzes with activity on weekends when shoppers from far and near stock up on supplies. 908 Philadelphia Avenue, Silver Spring. 589-8417. Hours: Daily 11 to 8; closed Wednesdays.

Sadana International, near the old Co-Op warehouse on New Hampshire Avenue in Takoma Park, is also well-stocked with Indian spices, dry goods, fresh produce, Mediterranean bread, crunchy snacks and sweets, and prices are often lower than at other Indian groceries. Sadana also stocks some hard-to-find items such as "kala namak" or black salt, used in North Indian cuisine, and unsweetened coconut cream bars imported from England. Coconut milk is an important ingredient in India's southern and coastal regions and coconut cream is a marvelous substitute for the tedious process of extracting fresh coconut milk. A small wedge of the cream dissolved into a shrimp or chicken curry tempers the pungency of the spices and serves to thicken the curry. 6857 New Hampshire Ave., Takoma Park. 270-2443. Hours: Open daily, 11 to 9, Sundays 9 to 8.

In the Rockville area, Exotic India provides a very necessary spice center for the Indian and Pakistani communities. Housed in a small modern shopping center next to the Hechinger plaza on Rockville Pike, Exotic India is clean with well-arranged shelves and a good supply of spices, lentils, rice, pickles and fresh produce. 593 Hungerford Drive, Rockville City Center Plaza, Rockville. 340-9345. Hours: Daily, 11 to 8; Sundays 12 to 6; closed Mondays.

India Spice & Gifts Store, 4110 Wilson Blvd., Parkington Shopping Center, Arlington. 522-0149. Hours: Daily 11 to 8; Sundays 11 to 7; closed Wednesdays.

International Foods, 7720 Wisconsin Ave., Bethesda. 986-8865. Hours: Daily 11 to 6. Closed Sundays.

India Emporium, 6848 New Hampshire Ave., Takoma Park. 270-3322. Hours: 10 to 8, daily and weekends.

Bharat Darshan, 1412 New York Ave. NW, Washington. 638-6827. Hours: 11 to 8:30 daily and weekends.

Indian Super Bazaar, 3735 Rhode Island Ave., Mt. Rainier. 927-2224. Hours: 10 to 7:30 daily; Saturdays 10 to 6; Sundays 10 to 5.