From The World of Cooking: Indian Cooking by Isabel Moore

Fry mustard seed in ghee until the seeds begin to pop. Stir in the garlic, cardamom, coriander, and ginger and fry 1 min, stirring constantly. Add the lamb and fry until browned. Stir in the onion, chilies, and sugar and fry until the onion is golden. Stir in the turmeric and spinach and cook 3 min. Add the remaining ingredients and reduce the heat to low. Cover and simmer for 1 hr or until the meat is cooked through and tender. Stir well.

Preheat the oven to 150 C/300 F. Put the casserole into the oven and cook 20 min. Remove from the oven and serve at once.