Here are two links for making Tarka Dal.
One is by Anjum Anand, the other by Manju Malhi and has a video.
www.bbc.co.uk/food/recipes/tarkadal_90055
www.videojug.com/film/how-to-make-tarka-dal
Tarka actually means adding last minute flavour by heating some oil or ghee or butter, adding spices to it like cumin seeds, mustard seeds, curry leaves, asafoetida, garlic, green or red chillies, cooking a few minutes, and then adding it all into the dal.
Fragrant yummy aromas!
Dal can be mashed or left whole, for a change.
A quarter teaspoon of Turmeric and a pinch of asafoetida are musts.
I don't use garam masala or onion generally. But I like to top dal with browned sliced onion sometimes. You can also add a few slices of ginger, even some bits of toasted coconut.
You can also stir-fry some chopped tomato and/or aubergine and add to dal, along with two teaspoons of coriander powder and one of cumin powder.
There are so many dals - toover or arhar, pink masoor, brown masoor, yellow mung, green mung, blackeyed peas, yellow peas, red beans, chickpeas, urad dal, lima beans, etc.