Fajitas, an elaborate north-of-the-border version of a simple Mexican dish, now come in some versions you'd rather not know about, such as chicken-fried-steak fajitas.

But here is one of the simpler versions of a fajita you do want to know about. It provides a mouth-wateringly good way to make a small amount of beef go a long way.And in place of ordinary sour cream, which is high in saturated fat, a mixture of non-fat yogurt and light ricotta cheese provides a more healthful way to come up with the texture and taste.

For your information: There is more than one type of light ricotta cheese. The one to seek out contains 1 gram of fat per ounce.

GAME PLAN

- Turn on oven.

- Slice beef and squeeze on lime juice.

- Prepare onion and red pepper and saute.

- Heat tortillas.

- Begin preparation of salsa.

- Add spices to vegetables.

- Add beef to vegetables.

- Whisk yogurt and ricotta.

- Finish salsa.

- Heat remaining tortillas.

NUTRITIONAL ANALYSIS

Per serving: 700 calories; 28 grams fat; 45 milligrams cholesterol; 557 milligrams sodium; 35 grams protein; 84 grams carbohydrate

FROM YOUR PANTRY

Olive oil

Ground cumin

Ground coriander

Non-fat plain yogurt

SHOPPING LIST

6 ounces flank steak

Lime

8 ounces whole onion or 7 ounces sliced or chopped onion (ready-cut)

12 ounces whole red pepper or 11 ounces sliced (ready-cut)

Package 10-inch whole-wheat or white-flour tortillas 1/3 Container light ricotta cheese (3 tablespoons)

1 jalapeno pepper

1 pound plum tomatoes

Small red onion (2 ounces)

1 small avocado

Bunch coriander (2 tablespoons)

1991 by Foxcraft, Ltd.

Excerpted from "20-Minute Menus," by

Marian Burros (Reprinted by permission

of Simon and Schuster; distributed by

Special Features/Syndication Sales)

Beef Fajitas

6 ounces flank steak

1/2 lime

8 ounces whole onion or 7 ounces sliced or chopped onion (ready-cut) (12/3 cups)

12 ounces whole red pepper or 11 ounces sliced pepper (ready-cut) (3 cups)

1 tablespoon olive oil

4 10-inch whole-wheat or white-flour tortillas

1 teaspoon ground cumin

1 teaspoon ground coriander

1/4 cup plain non-fat yogurt

3 tablespoons light ricotta cheese Heat toaster oven to 400 degrees. (If you don't have a toaster oven, use the regular oven.)

Thinly slice steak on the diagonal; place in small bowl and sprinkle juice from lime over it; stir and allow steak to sit while preparing rest of dish.

Peel and quarter whole onion; trim, seed and quarter whole pepper. Process with regular slicing blade of food processor. Saute in hot oil in large non-stick skillet until vegetables soften and begin to brown.

Wrap two tortillas in foil and place in oven.

Stir cumin and coriander into vegetables. Push vegetables to one side of skillet; add beef and brown on both sides.

Using wire whisk, beat yogurt with ricotta and set aside.

To serve, spoon 1/4 beef mixture on each of two tortillas, top with 1/4 salsa (see recipe) and 1/4 yogurt mixture. Fold over and serve.

Meanwhile, heat the remaining two tortillas and fill and top with remaining beef, salsa and yogurt. (Serves two.)

Avocado Salsa

1/2 to 1 whole jalapeno pepper

1 pound plum tomatoes

2 ounces red onion (1/2 cup)

1 small avocado

2 tablespoons chopped coriander

1/2 lime Wash and trim jalapeno pepper and seed. Break into small pieces and, with food processor on, put through feed tube to mince. Put in serving bowl.

Wash and trim tomatoes and slice on regular slicing blade of food processor. Slice onion. Coarsely chop sliced tomatoes and onion with knife and place in serving bowl.

Coarsely chop avocado and stir into salsa.

Chop coriander and stir into salsa.

Squeeze juice from lime into salsa and stir. (Serves two.)