You may need a formal introduction to the tamarillo, the fruit with a generous shelf life that can expand your quick-meal horizons. Its name suggests hybrid; does it sound too much like tomatillo? However, once you've cut into one -- with its distinctive dark seeds in reddish-golden flesh that tastes a little tart, a bit apple-banana -- you won't mistake it for a tomatillo, tomato or anything else.

The smooth-skinned, crimson-colored, egg-shaped tamarillo is hardly new. It was among the "lost crops" of the Incas that were rediscovered a while back. It was called the "tree tomato" until it was renamed commercially in 1967 in New Zealand, where most of the commercially grown tomatillo crop is now exported to the United States, according to Carolyn Lister of the New Zealand Tamarillo Growers Association.

New Zealand cooks and restaurant chefs tout its virtues in newsprint and on the Web (see www.tamarillos.com) and use tamarillos in condiments that accompany beef and pork, in muffins and slightly sweetened in sauces.

The fruit, a little larger than a jumbo egg, can be eaten plain, once the bitter skin is peeled, and retains its brilliant color when it's cooked. A little sugar or honey and a few hours' time can turn the fruit into an interesting and unusual dessert sauce.

Besides their versatility, tamarillos are otherwise handy to have around. Stored in the refrigerator, they can last up to three weeks, increasing the ease with which you can toss together a fresh-ingredient relish, such as the one featured in the quick dish below.

And, yes, they are nutritionally good for you: A single tamarillo contains 36 calories and is fat-free, cholesterol-free and a good source of fiber. It is rich in iron and potassium, with vitamins A, B6, C and E.

Look for tamarillos in some Washington area stores, such as Harris Teeter, until November.

Lamb Chops With Tamarillo Relish

4 servings

This light supper dish takes about 20 minutes to prepare. Serve with a pine nut and chopped parsley-studded couscous. Recipe adapted from Marlene Brown's "International Produce Cookbook & Guide" (HP Books, 1989).

1 tablespoon vegetable oil

4 tamarillos, peeled, seeded and sliced*

1/2 cup thinly sliced onion

1 clove garlic, minced

1/3 cup orange juice (may substitute water)

2 tablespoons red wine vinegar

1/4 cup (packed) light brown sugar

1/2 teaspoon salt

1/8 teaspoon freshly ground black pepper

Dash cayenne pepper (optional)

8 lamb rib chops (1 small rack, separated; about 11/3 pounds total)

Preheat the broiler and adjust the top rack so that it is about 4 inches from the broiler element.

In a large skillet over medium heat, heat the oil. Add the sliced tamarillos, onions and garlic, and cook until the onions are tender, about 3 minutes. Add the orange juice, vinegar, brown sugar, salt, pepper and cayenne pepper, if desired. Reduce heat to low and cook for about 10 minutes. Remove from the heat and set aside.

Meanwhile, place the lamb chops on a broiler pan on the top rack in the oven and broil 5 to 6 minutes on one side, then turn them over to finish the cooking, 4 to 6 minutes (for medium-rare).

To serve, place 2 lamb chops on each plate and spoon the tamarillo relish on top. Serve warm.

Per serving: 216 calories, 14 g protein, 18 g carbohydrates, 10 g fat, 42 mg cholesterol, 2 g saturated fat, 352 mg sodium, 2 g dietary fiber

Recipe tested by Bonnie S. Benwick; e-mail questions to food@washpost.com

*NOTE: To peel tamarillos, place them in a bowl, pour boiling water over them and let stand for 3 to 5 minutes (the skins will discolor from the heat), then slip off the skins and remove the stems.