Mango, Apple and Peach Chutney

1 large, extra-firm, unripe green mango (about 3/4 pound)1 large Granny Smith or any other tart apple (about 1/2 pound)2-3 extra firm unripe peaches (about 1/2 pound)1 tablespoon peanut oil1 teaspoon minced garlic1 teaspoon ground fenugreek seeds 1/4 teaspoon asafetida1 teaspoon black peppercorns20 whole cloves1 (3-inch) stick cinnamon5 black cardamom pods, pounded lightly to break the skins 1/2 teaspoon nigella or cumin seeds1 1/2 teaspoons salt, or to your taste2 cups sugar6 tablespoons white vinegarPeel, seed and cut the mango into large pieces, then grate it along with the apple and peaches. This can be done by hand or in a food processor fitted with the grating disk.In a large, heavy, stainless steel or other nonreactive saucepan, heat the oil over moderately high heat and cook the garlic and fenugreek, stirring, until golden, 1 to 2 minutes. Add the peppercorns, cloves, cinnamon, cardamom pods, and nigella seeds and stir for another minute. Mix in the grated fruits salt and sugar. Raise the heat to high and bring to a boil, stirring, for 4 to 5 minutes. (The sugar will melt and there will be enough liquid.)Reduce the heat to moderately low and simmer until the chutney becomes slightly thick, 15-20 minutes. Mix in the vinegar and continue to simmer until the syrup is thick and golden like honey, another 15 to 20 minutes. (Don't allow the chutney to become too thick, because it will thicken further as it cools.)Let the chutney cool completely, then put it in sterile glass jars. Store in a cool place. The color of the chutney deepens with the passing of time but that does not affect the taste. Always use a dry spoon when ladling it out, as added moisture will cause the chutney to spoil faster.Makes about 2 1/2 cups.Cook's note: Stays fresh for more than 1 year at room temperature. It does not need to be refrigerated until opened.Nutrition values per 2-tablespoon serving: 105 calories, 1 g fat (trace saturated), 25 g carbohydrates, 1 g fiber, 1 g protein, 0 cholesterol, 176 mg sodium.Adapted from "Chilis to Chutneys" by Neelam Batra (1997 William Morrow, $25)