Boil the eggplant on the stove directly or in the oven. When cool, Peel the skin off and mash. Add salt, asafoetida powder, green chillies, thick curd or buttermilk to the mashed eggplant. set aside. Heat little oil and add mustard seeds. allow it to splatter and add it to the pachidi. This is a good side dish for vettral kuzhambu.