Marinate the lamb with ginger juice, 1/2 cup of onion juice and a little salt for 30 odd minutes.
Heat the oil and 2 tbsp butter in a pressure cooker. Throw in the crushed cardamom, bay leaves and black peppercorn. Allow the spices to release their aroma.
Add the garlic, cook till light brown.
Now add the onion paste, cook till the smell of raw onions is no longer there.
Add the marinated mutton, the remaining onion juice, a little salt and 1/2 tbsp black pepper powder, cook over a low flame until the masala starts to release oil.
Add the carrots, potatoes and papaya batons. Splash a little water, cook for another 10-15 minutes.
Now pour in 2.5 cups of warm water, cover the pressure cooker and cook, 3 whistles I would reckon.
Remove from flame, allow the steam to release on its own. Adjust seasonings, sprinkle the remaining black pepper powder.
Finish with a dollop of butter.