Beat the curd and add 1 tablespoon ginger paste, 1 tablespoon garlic paste and 1 teaspoon red chilli paste, 1 teasooon oil. Mix it well and rub it to the mutton. Then add 1/2 teaspoon turmeric powder and salt and mix it well. Keep it to marinate overnight in the fridge.
Next day, heat the ghee in a deep and heavy pan.
Temper the oil with cinnamon stick, bay leaves and cardamom. Add the onion paste and fry until it turns light brown in colour.
Add the remaining ginger, garlic and red chilli paste. Fry until the raw smell of the masala paste goes away.
Cook until the oil gets separated and stir continuously. Add chopped tomatoes, mix and cook for some time.
Now add the marinated mutton and mix well. Add coriander, red chilli powder and remaining turmeric powder then stir and add salt.
Cover and let it cook for sometime, then stir so that it doesn't burn.
Keep doing this process for 20-25 minutes till the mutton is soft and all the water is released.
In between, uncover and check for burning at the bottom, if required sprinkle water.
Now transfer the mutton to a pressure cooker and add 1 cup of water. Close the lid and let it cook till 3 whistles blow, do this under a low flame.
Turn off the stove. Wait till all the pressure is released. Open and add the fried potatoes.
Cover the cooker with a lid and allow it to cook until 1 whistle blows under a low flame. Wait till all the pressure is released, then open and add the garam masala. Cover and cook for 2 minutes.
Stir to mix everything together and cook on a low flame for 2 minutes.
Turn off the gas and serve it with hot steamed rice.