Preheat oven to 350º. In a shallow baking dish, place onion rounds, cut side down, in one layer. Sprinkle with ¼ c. water and cover with aluminum foil, sealing tightly. Bake 30 minutes or until tender. Combine remaining ingredients in a small bowl. Turn onions cut side up and spoon mixture over them. Bake uncovered for about 15 minutes, then baste thoroughly with any remaining mixture or juices in the pan. Return to oven, and continue baking another 15 minutes or until golden. Plate and serve hot.