Trim excess fat from lamb; cut into 1.5 inch cubes. Heat oil in a heavy saucepan; add onion. Cook until softened; add cardamom, turmeric, chile powder, cumin, paprika, coriander and masala.
Cook, stirring, 2 to 3 minutes, then stir in yogurt and tomatoes and bring to a boil. Add lamb cubes and stir well.
Bring to a boil then reduce heat, cover and cook 40-50 minutes until lamb is tender, and liquid makes a thick sauce, stirring occasionally.
From the Dinner Co-op