Preheat the oven to 150°C.
Season the meat with salt and pepper. In a food processor or using a mortar and pestle grind together the coriander seeds, chillies, nutmeg, paprika, aniseed, mustard seeds and oregano until fine.
Add the sugar and roll the shanks in the spice mixture, pressing it in well. Dust the meat with the flour.
Heat the oil and butter in a heavy-based casserole and brown the meat on all sides. Remove from the casserole.
Saut&eacte; the onions in the same pan until transparent. Add the garlic, carrots, canned tomatoes, ginger and rosemary (or lavender) and simmer until the vegetables have softened.
Add the vinegar and reduce to a syrup.
Add the wine and simmer for 5 minutes.
Add the tomato purée, mix gently and return the lamb to the pan.
Bring to the boil, cover tightly with the lid or aluminium foil and simmer in the oven for 2 hours.
Remove the lid or foil and cook further until the meat becomes crispy on the outside.
Skim off any fat and adjust the seasoning if necessary.
Stir in the basil and orange rind just before serving.
Serve the shanks with couscous.