Preheat oven to 350°F / 180°C / Gas Mark 4 Roast the Pine nuts; on a dry pan at 350°F in the oven for about 3 minutes to release the flavour and set aside.
On the stove top; sear lamb in the olive oil. Add the onions; sauté for about 2 minutes; then add the garlic and sauté for about 1 minute. Add turmeric, nutmeg, cardamom, crushed red pepper and cinnamon and sauté the mixture for 1 to 2 minutes longer, being careful not to burn the onions or garlic. Add the tomatoes and veal stock and stir.
You can substitute the veal stock for beef stock.
Cover the dish and bake at 350°F. for about 1 hour, until the meat is tender and begins to break up. Remove the dish from the oven and add the spinach, stirring until the spinach is wilted and blended in. Taste the dish and add salt if needed.
Allow the stew to cool slightly. Add the yogurt and lemon peel. Sprinkle with roasted pine nuts.