Heat oil in a pan, add mustard and urad dhal. Add finely sliced onion, saute it well until it is soft and pink. Now add finely chopped tomatoes and saute it well, until it is soft and well cooked. Now add sliced brinjals and saute it. Add chilly powder, coriander powder, turmeric powder and salt, mix well, cover it and leave it cook. Once the brinjal is cooked remove the lid and saute it unitl it is well roasted and crisp. Garnish with curry leaves and serve.
Suggestion: Tomatoes cook fast, when the pan is covered with a lid for a couple of minutes,cook on low heat to avoid burning. It tastes good with rasam saadam, sambhar saadham and curd rice.