Heat a dry saucepan with oil and fry the
mustard seeds until the seeds pop. Add chili and onion. Fry until onion
is soft. Add eggplant and fry for another few minutes, stirring. Then
add salt, garam masala, tomato and chili powder. Stir well, add water,
cover with a lid and cook until the eggplant and tomato can be mashed to
a puree. Cool, stir in yogurt and half the cilantro leaves. Serve
garnished with remaining leaves.