In a pressure cooker, take the Toor dal, onions, tomatoes, green chilli, turmeric and 2 cups of water. Cook them for 3 whistles.
Let the steam out, open, add salt and mix well.
Take a deep non-stick pan and sauté oil, cumin seeds, garlic, asafoetida, red chilli and curry leaves.
Sauté for 30 seconds in medium flame; then add red chilli and sauté for 30 seconds.
Add the dal mixture. Mix well and cook for 4 minutes on medium flame.
Add coriander and serve hot with rice.