Morrocan Lamb Shanks

2kg lamb shanks
2tbsp Ras el Hanout spice blend
2 onions, cut into 1-inch cubes
2 carrots, peeled, cut into chunks
3 cloves garlic, minced
1cm freshly grated ginger
1 lemon, zested
2cups chicken stock
1tbsp tomato paste
1tbsp honey

Drizzle a little olive oil over the lamb shanks, rub the Ras el Hanout all over the shanks, leave them to marinate in the fridge for at least 8 hours, preferably overnight.
Heat 1 tablespoon of olive oil in a large, heavy bottomed pot over medium-high heat. Add the shanks 2 at a time, and brown well. Remove to a plate, and repeat with remaining lamb. Add onions and carrots to the pot and cook for 5 minutes. Stir in the fresh garlic and ginger; continue cooking for an additional couple of minutes.
Place the vegetables in the bottom of a casserole dish that has a well fitting lid and stir in the lemon zest, chicken broth, tomato paste, and honey. Put the lamb on top of the vegetables, turning them to ensure they are covered in the sauce. Cover the casserole, Place in a hot oven for 30 minutes, then reduce heat to moderate and simmer for around 2 hours.
Serve with Couscous.