Cook thuvar dhall and keep it aside. Boil beans and potatoes, add a little salt and turmeric to this. Wet grind coconut, poppy seeds, mustard, and red chilles. Add this masala to the boiling vegetables, and cook until the flavour comes out. Add the cooked thuvar dhall and let it boil for a few minutes. Heat some oil in a pan, splutter little mustard, then add curry leaves, little hing, and add this to the above.