Peel the potatoes, cut into halves horizontally into equal halves. Wash and keep aside.
In a cooker add freshly washed pieces of mutton and 1/2 tsp salt. Adjust water to level the mutton in the pressure cooker. Close the cooker lid and take off the flame after 4 whistles. Open the lid after the pressure has reduced. Keep the stock aside.
Fry the potatoes, let them turn golden brown, remove and keep aside.
Heat oil in a deep frying pan. Temper with dry red chilli and bay leaf.
Add sugar, just gently stir the sugar until all of it turns golden brown.
Then add crushed black peppercorn, cumin powder, coriander powder, turmeric powder, Kashmiri mirch powder, green chillies, salt and ginger paste. Mix and fry it on medium heat until the masala starts leaving oil.
Add the mutton pieces and potatoes. Mix well with the masala and fry on medium heat for 10-15 minutes, stirring consistently.
Now add some mutton stock in this (one ladleful at a time), mix and fry for 4-5 minutes. Add some more stock. Repeat this process for 3-4 times and cook on medium heat.
Finally add rest of the stock, mix, cover and cook on a low flame until the meat is fully cooked, stirring consistently.
Add garam masala powder, mix and remove from heat.
Serve hot with steamed rice, luchi, ruti, puri, paratha, whatever you like.