Cook toor dal by adding a pinch of turmeric and baking powder. In a frying pan heat little oil and add mustard. When it splutters add fenugreek seeds, coriander seeds, cumin seeds, channa dal, urid dal, green chillies, garlic if used. When they are ready add the cut onions and fry till golden brown. Now add the tomatoes and cook till the tomato is tender. Add the cooked dal to this. If it is thick add water and stir. Add salt, asafoetida and red chilli powder if required. Serve hot with chapatti.