Wash the mutton and pat it dry.

In a bowl, mix curd, mace powder, salt, and half of the ginger and garlic paste.

Add the mutton to the bowl and ensure it's well coated with the mixture.

Cover and refrigerate for at least 2 hours, preferably overnight.

Place a pressure cooker on medium heat and add mustard oil.

Add sliced onions and fry until golden brown.

Add ginger and garlic paste, water, peppercorns, cloves, red chilli, chilli powder, turmeric powder, cumin powder, salt, and crushed black cardamom.

Add the marinated mutton to the pressure cooker and stir-fry for 15 minutes.

Add 1/2 cup of water, close the lid, and cook on medium heat for 5 whistles.

Check for salt and tenderness. If needed, add 1/4 cup water and cook for a few more whistles.

Open the lid, add green cardamom powder, and let it rest for 15 minutes before serving.

Serve hot with Rumali Roti and Mooli Raita.