2 x 800g/28oz racks of lamb ribs (you may think that this is too many ribs for four people but they do shrink a lot) 1/2 cup olive oil 2 tablespoons sumac 2 tablespoons ground cumin 2 tablespoons Turkish red pepper 1 tablespoon salt A good grind of black pepper 2 teaspoons smoked paprika 2 cloves garlic, finely chopped 3 tablespoons brown sugar 1 tablespoon fish sauce 1 tablespoon tamarind paste 1 lemon to serve