In a pressure cooker or a deep pan, heat oil, add the mustard seeds, urad dal,cumin seeds,dry red chillies,curry leaves and asafoetida powder. Mix well and cook for a minute.
Add the chopped onion and garlic and cook for another minute.
Add chopped tomatoes, carrots, beans or eggplant, sauté for 5-7 minutes until the veggies are half done.
Add in the salt, sugar, soaked and drained toor dal, sambhar powder, coriander powder, tamarind concentrate and 1.5 cups water (350ml).
Pressure cook for 1 whistle or more(depends on how mashed you want the lentils). If cooking in a pan, cover and cook on low heat for 20 + minutes.
Serve hot as side curry, topped with chopped cilantro, with Roti(Indian bread) and a dry veggie dish(subzi)!