Smoke the baingans directly on the gas flame. When cooked and soft, cool and peel the skin. Then mash the flesh. Sauté the chopped onions, tomatoes and ginger in a wok. Add the mashed baingan, salt and chilli powder. Mix in the peanut yoghurt and serve hot.
You could replace the yoghurt with lemon juice.
You may temper with spices like mustard seeds, crushed chilli, coriander seeds and asafoetida.