Preheat oven to 450° F. In heavy skillet heat oil over moderately high heat until hot and in it brown the racks of lamb, seasoned with salt and pepper, 1 at a time, for 3 to 4 minutes. Transfer the racks to a roasting pan, fat and meat side up, and roast in the middle of the oven for 15-20 minutes, until meat thermometer registers 130° for medium-rare. Transfer the lamb to a cutting board, let it stand, uncovered, for 10 minutes, and slice it into chops. Divide the chops among 4 heated plates and spoon dollops of the chutney on each plate. Serves 4. HERBED TOMATO CHUTNEY 1-1/2 lbs. plum tomatoes, peeled, seeded, and quartered 1-1/2 cups chopped onion 1/3 cup sugar 1/3 cup white-wine vinegar a 1-inch piece of peeled fresh ginger root, minced 1 bottled pickled jalapeno chili, seeded, chopped fine (wear gloves) 1 teaspoon coriander seeds 1 teaspoon mustard seeds 3/4 teaspoon salt 1 tablespoon chopped fresh rosemary or 1/4 cup shredded mint In a heavy saucepan toss together gently the tomatoes, the onion, and the sugar and let the mixture stand for 2 hours. Stir in the vinegar, the ginger root, the jalapeno, the coriander seeds, the mustard seeds, and the salt and simmer the mixture for 10 minutes. Transfer the solids with a slotted spoon to a bowl, pouring any accumulated liquid back into the pan, and boil the liquid until it is reduced to about 1/2 cup. Stir in the rosemary or the mint and pour the liquid over the tomato mixture. Stir the chutney gently and chill it, covered, for 2 hours, or until it is cold. The chutney may be made 5 days in advance and kept covered and chilled. Serve the chutney chilled or at room temperature. Makes about 2 cups.