Heat olive oil in a large casserole over medium-high heat. Brown the lamb shanks on all sides until well seared.

Remove lamb and set aside. Add chopped onions to the same pot, lower heat to medium, cover, and sweat for 10-15 minutes until soft and translucent.

Return lamb to the pot with garlic, turmeric, ginger, salt, pepper, saffron, coriander bouquet, and 1 1/3 cups water. Bring to a boil, cover, and simmer gently for 2 hours until the meat separates easily from the bone. Check after 1 hour and reserve 1/2 cup cooking liquid; add water if needed.

Prepare the caramelized prunes: soften prunes in boiling water for 5 minutes, then drain. Simmer with the reserved cooking liquid, cinnamon, and honey for 5 minutes until the sauce thickens into a glossy syrup.

Plate the lamb shanks with the onion sauce, spoon the caramelized prunes and syrup over the top, and garnish with toasted sesame seeds. Serve with couscous or crusty bread.