EXOTIC VEGETABLES. What's a calabaza, and how do I cook it?

TODAY'S neighborhood supermarkets are peppered with so many flashy new vegetables you can hardly find the spinach -- or the carrots or the peas or the pale tomatoes. Round, red heads of Italian radicchio, trendy and expensive, are up front, alongside giant-yellow and deep-purple bell peppers, daikon radishes, bumpy, bitter melons, enoki mushrooms, and all kinds of ``edible exotics'' you've read about or seen on the menus of the newest restaurants.

While they may not be as American as pizza and apple pie, unusual vegetables are rapidly being assimilated into the spinach-and-peas slot on the menu.

``In the last 10 years,'' says Nancy Tucker of the Produce Marketing Association, ``the average number of items available in produce departments has doubled from 70 or 80 to more than 200, some up to 250.''

Farmers in southern Florida are replacing groves of limes and papayas with yucca, calabaza (a squash), pigeon peas, yard-long beans, and calamondin, a citrus fruit used for seasoning fish and meat. In Mississippi, Vietnamese farmers are growing lemon grass; bok choy is grown by Chinese in New Jersey; and Japanese vegetables such as slender eggplant and kabocha squash can be found on California farms.

``Whatever the grocer puts on the produce stands that's fresh and different, people will try,'' says Frieda Caplan, whose specialty produce company in Los Angeles sells to every major food retailer in the country.

The average American's growing taste for the new, different, and foreign has paved the way for all kinds of exotic foods. The influx of ethnic populations, Asian and Hispanic in particular, has contributed to the trend, as has smart merchandising and packaging.

Ms. Caplan has helped introduce to supermarkets the type of vegetables previously found only in gourmet shops. Starting with kiwi fruit and Jerusalem artichokes, she added sugar-cane sticks, enoki mushrooms, jicama, and passion fruit to her line. When she saw that mini vegetables were a coming trend, she found farmers to grow mini gold squash, tiny carrots, and baby artichokes for her company.

Now a $9 million business, Frieda's Finest ships more than 200 different fruits, vegetables, and herbs -- all tagged with her bright purple label and a recipe or preparation information.

That recipe on the label is one of the reasons why this produce company is successful. One of the first things a customer asks about a new vegetable is ``How do I cook it?'' Although there are dozens of cookbooksthat zero in on vegetables, most tend to be pretty traditional.

One new one stands out. It's called ``The American Vegetable Cookbook: The Definitive Guide To America's Exotic & Traditional Vegetables,'' co-authored by Georgeanne Brennan, Charlotte Glenn, and Isaac Cronin (Aris Books, $14.95).

The book explains what to do with everything from fennel and lotus root to yucca, jicama, and nopales (cactus leaves). It also includes an illustrated index of unusual vegetables. If you know what a certain vegetable looks like but can't remember the name, find the shape you recognize and you'll be referred to the page number on which the item is described.

Vegetables are grouped by botanical families, for those who don't know that parsley is in the carrot family or that spinach is in the goosefoot family.

The authors share imaginative ways of preparing vegetables and also have good ideas about growing and picking them.

The cookbook includes recipes and preparation instructions for familiar vegetables as well as new ones. From Ms. Glenn's years in Georgia there's a recipe for Sweet and Sour Okra and Black-Eyed Peas with Spicy Sausage and Tomato Coulis. Ms. Brennan's French background is indicated in Fresh Pea Soup with Chive Blossoms and Roast Peppers Stuffed with Garlic and Goat Cheese.

Here are some recipes from their new vegetable cookbook. Fresh Pea Soup With Chive Blossoms And Cr`eme Fra^iche 2 pounds green peas, shelled 3 cups chicken stock Salt and pepper to taste 2 tablespoons cr`eme fra^iche 2 tablespoons chive blossoms for garnish

In a large saucepan cook peas in stock until tender, 10 to 20 minutes depending on size and freshness.

Season with salt and pepper. Pur'ee in food processor or blender. Strain liquid if you want a light broth. Serve as is if you prefer a thicker soup.

Top each bowl with cr'eme fra^iche and sprinkle with chive blossoms. Chive blooms have a wonderfully subtle onion flavor, but if you prefer you can substitute mint, chamomile, or nasturtium flowers, or chopped fresh chives. Instead of peas, asparagus can also be used. This soup is delicious cold as the first course of a brunch or light lunch. Serves 4 as a first course.

This salad -- a variation on the three-bean salad -- is a textural delight for those who love crunchy vegetables. Serve it as a cooler with spicy food. Three Crunch Salad 1 small jicama 1/2 pound fresh water chestnuts 1/2 pound Jerusalem artichokes 1/4 cup peanut oil 3 tablespoons fresh lime juice 1 tablespoon chopped fresh cilantro Salt to taste

Peel vegetables, placing each one in acidulated water after peeling. Slice water chestnuts and Jerusalem artichokes into thin slices. Cut jicama into 1/2-inch cubes. Serves 4 as first course. Chinese Stuffed Peppers 3/4 pound ground pork 1/4 pound cooked baby shrimp 1 teaspoon grated fresh ginger 1 tablespoon medium soy sauce 1/4 cup chicken stock 1 tablespoon peeled, chopped fresh water chestnut or Jerusalem artichoke 1 to 2 tablespoons cilantro leaves, chopped 1 teaspoon cornstarch 4 green, red, or yellow bell peppers Dipping Sauce 2 tablespoons chicken stock 2 tablespoons medium soy sauce 1 teaspoon white sugar 2 teaspoons grated fresh ginger 1 tablespoon Asian sesame oil

In a mixing bowl or food processor combine stuffing ingredients. Carefully cut off tops of peppers. Remove seeds and pulp. Stuff each pepper with 1/4 of pork mixture. Add tops. Steam until peppers are soft, 15 to 20 minutes.

Meanwhile, mix all dipping sauce ingredients except sesame oil in saucepan. Bring to boil and immediately remove from heat. When partly cool add sesame oil. Pour sauce over peppers and serve.