You can brown the lamb, if you like, in a heavy skillet or saute pan in a little olive oil over high heat. Set aside.

Melt the butter in the bottom of a tagine. Add the onions and cook for 10 - 15 minutes, until tender and sweet.

Add the garlic, ginger, turmeric, and cayenne pepper and cook for a few minutes. Add the lamb and just enough water to barely cover the meat. Cover and simmer gently for about 1 1/2 hours, until the meat is tender.

Pack the mint, cilantro and jalapeno into a blender. Add 2 Tbsp of the lemon juice and 1/2 cup of the stew juices and puree. Add the mixture to the lamb stew and simmer for a few minutes. Adjust the ginger, cayenne, lemon juice, salt and black pepper to taste. Serve with saffron rice.