Fry sliced onions until crisp golden brown, then blend with cashews into a paste.
Marinate mutton with yogurt, ginger paste, garlic paste, red chili powder, Kashmiri chili powder, and salt.
Heat ghee in a pressure cooker, add mutton, and sear for 10 minutes.
Add crushed onion-cashew paste, garam masala, and 1 cup water.
Pressure cook for 6 whistles until tender, then simmer for 5 minutes before serving.