Heat one teaspoon of oil in a non stick pan. Add dhuli urad dal and sauté for half a minute. Add coriander seeds, methi dana and red chillies and sauté till fragrant, taking care that the spices do not burn.
Grind with the coconut, tamarind pulp and three tablespoons of water to a semi coarse paste. Heat the remaining oil in a non stick kadai. Add the mustard seeds and when they splutter, add the curry leaves, asafoetida and turmeric powder.
Add the onion and sauté till golden. Add the potato cubes, stir well and cover with lid and cook for three to four minutes. Remove lid and add cauliflower. Stir well again.
Cover and cook on low for seven to eight minutes heat or till done. Remove the lid. Add the coconut masala, half a cup of water and salt to taste. Stir well and cook for two to three minutes. Serve hot.