Trim excess fat from lamb shanks and season generously with salt.

In a bowl, mix together cinnamon, nutmeg, cardamom, rosebuds (if using), black pepper, and turmeric.

Rub the spice mixture evenly over the lamb shanks.

Let the seasoned lamb shanks sit at room temperature for at least an hour, or refrigerate overnight and bring to room temperature before cooking.

Preheat oven to 350 degrees F (175 degrees C).

Heat vegetable oil in a Dutch oven or deep, heavy pot over medium-high heat.

Brown the lamb shanks on all sides, about 5 minutes per shank. Remove and set aside.

In a small bowl, steep saffron in lime juice, 2 teaspoons rosewater, and 1/2 cup warm water for 10 minutes.

Remove all but 2 tablespoons of oil from the Dutch oven.

Add chopped onion and cook over medium heat until softened and lightly colored, about 8-10 minutes. Season with salt.

Add lime zest, orange zest, thyme sprigs, and bay leaves to the onion mixture. Stir in the saffron mixture.

Lay the browned lamb shanks in the Dutch oven and add chicken broth or water.

Bring to a boil, then turn off the heat and cover the pot.

Transfer the pot to the preheated oven and bake for about 1 1/2 hours, or until the meat is tender and starting to fall off the bone.

Remove the lamb shanks from the Dutch oven and place in a deep serving dish. Keep warm.

Strain the braising juices through a fine-mesh sieve into a bowl, pressing to extract all the liquid. Discard the thyme, bay leaves, and onions.

Skim the fat from the strained juices. Taste and add salt if needed.

Add 1 more teaspoon of rosewater to the juices, if desired.

Reheat the strained juices and pour over the lamb shanks.

Combine parsley, mint, and reserved orange zest. Sprinkle over the lamb shanks.

Use a large spoon to break the tender shank meat into large chunks.

Serve in low, wide soup plates with a spoonful of the braising juices.

Serve with steamed Basmati rice, lavash flatbread, or crusty French bread.