In a sense, turmeric is an all-American spice. It's used at sports events, Fourth of July picnics and barbecues, even dispensed at McDonald's. It's what makes mustard yellow, so in popular American mustards -- dijon mustards have only traces at most -- turmeric is practically as important as mustard seed.

The irony of a turmeric-laden condiment being slathered on hot dogs and hamburgers is that turmeric is one of the most ancient and exotic of the Asian spices. Like its cousin, ginger, it's a tuber-like stem or rhizome, and it has been dug out of the hilly jungle areas of tropical India and Southeast Asia for thousands of years, mostly for medicinal purposes.

The fact is that turmeric, even today, is used in Asia mostly because of its ages-old reputation as a healer with spiritual dimensions. Besides a pleasant, very subtle woodsy fragrance, it really doesn't do much for food.

Turmeric's value as a dye, whether for cloth or for food, is another matter. It's so routinely used in India and it's so inexpensive that the packagers of commercial curry powders incorporate an inordinate amount of it in their mixtures, enough so that those whose only inkling of Indian food comes through using curry powder must get the impression that Indian dishes are brilliant yellow and leave a stain.

Until recently turmeric was sold only as a yellow-orange powder. The dried rhizome can now be found at Indian spice shops and Southeast Asian markets. However, while turmeric -- like any spice -- is better freshly ground, the whole woody rhizome will surely break the blades of a small spice grinder. Sliced or chopped, fresh turmeric -- which looks like small, orange-tinted ginger roots -- is added to the stews we call curries. TURMERIC POTATOES (6 to 8 servings)

This simple recipe is adapted from Julie Sahni's "Classic Indian Cooking." It's good hot or at room temperature.

6 medium-sized potatoes (2 pounds)

2 teaspoons coarse salt

1 1/2 teaspoons turmeric

4 tablespoons peanut oil

2 green serrano chili peppers, sliced

1/2 teaspoon pepper

2 tablespoons chopped fresh coriander

Boil the whole potatoes about 6 minutes. Drop into cold water briefly and peel. Cut into 3/4-inch cubes and put them in a bowl. Toss with the salt and turmeric and set aside.

Over a medium flame, heat the oil in a skillet until hot. Add the potatoes and cook, stirring for 5 minutes. Add the chili peppers and stir briefly. Add 1/4 cup of water, stir briefly, then turn the heat to low and cover. Cook for 10 minutes then uncover and cook stirring until the potatoes have a brown crust. Toss with the pepper and fresh coriander and serve.