Cut the egg plant into quarters lengthwise. Heat oil in a pan add mustard seeds. When it pops add the urad dhal and fry until golden. Add ginger, garlic and fry for few minutes. Then add the chopped onions and fry until it is translucent. Add the chopped tomatoes and mix well. Then put the egg plant and fry for few minutes. Add red chili powder, turmeric powder and salt. Mix well and pour little water. Cover the pan. Lower the heat and cook until the egg plant is done and the gravy becomes thick. Garnish with chopped cilantro leaves.