Boil meat in 2 cups water, half of ginger, garlic paste and salt, until tender.
Boil dal seperately in little water and salt. The dal shouldnt be mushy.
Take oil in pan ,add whole spices, and green chillies,when they splutter add onions and fry till golden brown.
Peel and chop the tomatoes, add to the onions .add tomato puree, remaining ginger ,garlic paste, turmeric powder and salt. Braise for 10 mins on medium heat.
Add meat ( not the soup ) dal and potatoes, cover and cook for 15 mins on low heat,till all spices blend properly with meat.
Open the cover , add soup , garam masala pwd and lemon.