1. Heat the oil in a casserole and cook the onion over medium-high heat,
stirring constantly, until soft.
2. Stir lamb, coriander, mustard seeds, cumin, chili powder and turmeric.
3. Mix all the ingredients well.
4. Add 1 tbsp of yogurt and cook over high heat, stirring the meat until all the yogurt is absorbed, about 3 to 5 minutes.
5. Repeat with the second tbsp of yogurt, third, and so on. When the yogurt is used up, stir in the ginger and garlic, add just enough water to cover the meat and bring to boil.
6. Cover the casserole, lower the heat and simmer for one hour.
7. When the meat is cooked, increase the heat to medium and add the
spinach in batches, stirring each batch until it is wilted.
8. When all the spinach is incorporated, cook the stew, uncovered, over high heat to evaporate any excess liquid, about five minutes. Add the salt just before serving.

Serve with rice and pappad.

Serves 6.