Method:

1. Heat oil - add the items under 'to saute and grind' except coconut and fennel seeds. Add it along with coconut and fennel seeds and grind it to a fine paste.Set aside.
   
2. Add lemon sized tamarind in 1/4 cup water, extract juice and mix with the grinded paste and keep aside. Soak the dals in water for 2 hrs.
   
3. Then drain water from the dal, grind it with red chillies, fennel and salt to a semi coarse mixture. Do it in batches if you are using a small mixer like me. No need to add water while grinding.Collect it in a bowl , add coconut and mix well. Adjust salt at this stage.
   
4. Make lemon sized balls out of it and keep aside. Heat oil in a kadai and add the ingredients under 'to temper' one by one saute for 2mins until onions start browning.
   
5. Add 3 cups of water with chilli and coriander powder and allow it to boil. Once the water starts boiling, simmer and gently add the lentil balls one by one taking care not to mush it.
   
6. Allow it to get cooked, dont turn over which will make the balls mushy. Once the balls are cooked it will become firm, then you can turn over once and thats the stage you have to add the grinded paste + tamarind pulp.Add required salt and mix well. Now let the gravy thicken and boil for few minutes until oil seperates. Simmer it after boiling and let it cook for another 2-3 mins. When the gravy is as thick as in the below pic, Switch off and garnish with chopped coriander leaves.
   

I have watched amma making it many times and wanted to give a try and this is the 2nd time I'm trying it myself....Its my favorite gravy with rice. The lentil balls in coconut tamarind sauce tastes best, I luv it even with dosas and chapathis. This seems to be a lengthy process but once you taste it am sure you will not regret for the pain taken.

My Notes:

• I was very much skeptical about adding the lentil balls as such in the gravy but it works fine. I've heard from my friends that the balls need to be steamed before adding it to the gravy but I find adding it directly is messfree and easy.
• Be careful in turning over the balls before its cooked. Also add them only after the water starts boiling and dont forget to simmer after the balls are added.
• The texture of the balls is purely your choice, we usually like it a bit smooth. You can make it even more coarse too.