1. To prepare chicken:
Place chicken breasts and DANNON Plain yogurt in large, nonñmetal bowl. Peel onions and dice into oneñquarter inch squares. Add rosemary leaves, 1/4 teaspoon cumin, 1/2 teaspoon salt and freshly ground black pepper. Mix well. Cover and refrigerate 3 to 4 hours.
2. Preheat oven to 375∞ F. Place chicken breasts covered with yogurt and onion mixture in heavy shallow baking pan. Bake 20 minutes. Prepare sauce (see below).
3. Remove pan briefly from oven and drizzle 1/2 teaspoon oil over each chicken breast. Place pan under broiler for 5 minutes until onions begin to blacken and chicken is cooked to desired doneness. Serve immediately with sauce. Garnish with fresh cilantro leaves, if desired.
4. To prepare sauce:
In small bowl, mix DANNON Plain yogurt, olive oil, cumin and onion puree. Add salt to taste. Set aside.