Peel the potatoes and cut them in halves. Roughly dice the carrots. Finely chop ginger and garlic. Roughly quarter the onions. And deseed the tomatoes, discard the skin and cut them into quarters.
Wash the mutton pieces and pat them dry.
Take a pressure cooker and heat 1 tbsp mustard oil. Add the whole spices and let them brown a little bit.
Then throw in the onions, ginger and garlic and saute them for a few seconds.
Add the mutton pieces and start browning them on medium to high heat. While doing that, add black pepper and salt. Keep browning and then add the tomatoes.
Stir for a couple of minutes. Add 2 cups of water, give it a boil and close the lid of the pressure cooker.
Take a frying pan, heat half tbsp mustard oil and fry the potatoes and carrots till they have a mild colour but are essentially raw.
When the mutton is cooked halfway, remove the lid and add the vegetables including the green peas. Give another boil and cover the lid and cook the mutton all the way.
When done, wait for the pressure to release. Then remove the lid and add green chillies, more black pepper powder, salt, sugar, butter and a tsp of flour mixed with a couple of tbsp of water to thicken the soup.
If you want to keep it thin, then no need to add the flour slurry.
Garnish with fresh coriander leaves and serve hot.