Preparation / Directions:
Lightly roast the cumin seed and coriander seed by frying with no oil for minute or so, stirring constantly. Grind these and combine them into paste with other spices, garlic, ginger and the vinegar. Add the lamb to the marinade and mix well. Refrigerate for 3-24 hours while mixing every few hours as convenient. Finely chop the onions and potatoes and saute them for 5 minutes in the butter. Add lamb and spice paste and simmer over low heat for half an hour. The marinating does add a lot of flavor and makes the meat much more tender. This can be skipped if need be. Based on Dharamjit Singh's recipe in "Indian Cookery: A Practical Guide.