Cut the meat into 3 cm cubes. Finely chop cumin, coriander, cardamom, fenugreek, chili powder, turmeric and mustard powder together in a blender.
Heat the ghee or clarified butter in a saucepan. Brown the meat in several portions all around. Remove. Add the onions, ginger, garlic and cinnamon stick to the saucepan. Steam while stirring until soft. Mix in the spices and meat again. Add the vinegar, beef stock, sugar, salt and pepper. Cover and cook over low heat for about 1 1/2 hours.