PreparationMake spice paste: Mince garlic with salt and mash to a paste. Wearing protective gloves, mince chile (including seeds for a spicier paste) and in a bowl stir together with garlic paste and remaining spice paste ingredients. Make 3 diagonal cuts about 1/4 inch deep in each chicken breast and rub spice paste into cuts and all over chicken. Marinate chicken, covered, 30 minutes at cool room temperature. Preheat broiler and line broiler pan with foil. Halve onion through root end and reserve 1 half for sauce. Thinly slice remaining onion half, separating layers, and in a small bowl soak onion slices in ice water to cover while broiling chicken. Arrange chicken without crowding on rack of broiler pan. Brush chicken with 1 teaspoon vegetable oil and broil about 3 inches from heat 8 minutes. Turn chicken over and brush with remaining teaspoon vegetable oil. Broil chicken until lightly browned and just cooked through, about 6 minutes more. Make sauce while chicken is broiling: Mince enough reserved onion to measure 1 tablespoon and in a small bowl stir together with all sauce ingredients. Drain soaked onion and pat dry between paper towels. Top chicken with onion slices and serve with yogurt sauce. Each serving, including yogurt sauce, about 222 calories and 5 grams fat. Nutritional analysis provided by Gourmet