Soak whole masoor dal for 4-6 hours.
Boil massor dal by adding the chopped potatoes and little salt.
For 1/2 cup sabut masoor dal, I added 1 and 1/2 cups water to the pressure cooker and cooked for 4-5 whistles. Switch off the gas and keep this aside.
After it cools, drain the water. Do not discard the water. This can be later added to the gravy if it turns thick.
In a kadai/wok, add 1 tablespoon oil, and fry onions till they turn pinkish.
Add garlic and fry till it becomes aromatic.
Add all the masala (red chilies, coriander seeds, peppercorns and cloves) and fry for some time.
To this add grated coconut and fry till coconut turns brownish. Make sure to fry on low flame.
Once it gets fried switch off gas.
Mix turmeric powder and stir.
Drop the tamarind ball in the kadai while the coconut and masala contents. Let it cool down.
Grind this into smooth gravy by adding 3/4 cup water or as required.
Now switch on the gas and in the same kadai (kadai will be empty as the contents are ground), add the gravy. Let the gravy get cooked for 5 minutes, then add the boiled masoor dal to the gravy. Add garam masala and give a nice stir. Cook for 10 minutes and switch off the gas.
Add salt per taste.