Preheat your oven to 325°F (160°C).

In a dry skillet over medium heat, toast the mustard seeds until they start to pop and become fragrant, about 2-3 minutes. Remove from heat and let cool.

In a small bowl, combine the toasted mustard seeds, dried oregano, dried thyme, dried rosemary, minced garlic, olive oil, salt, and pepper to create a herb crust mixture.

Pat the lamb shanks dry with paper towels. Rub the herb crust mixture all over the lamb shanks, ensuring they are well coated.

In a large oven-safe pot or Dutch oven, heat a little more olive oil over medium-high heat. Sear the lamb shanks on all sides until browned, about 5-7 minutes. Remove the shanks and set aside.

In the same pot, add the broth, pomegranate juice, and balsamic vinegar. Bring to a simmer, scraping up any browned bits from the bottom of the pot.

Return the lamb shanks to the pot, spooning some of the liquid over them. Cover the pot with a lid and transfer it to the preheated oven.

Cook in the oven for about 2 to 2.5 hours, or until the lamb is tender and easily pulls away from the bone.

Once done, remove the pot from the oven. Carefully take out the lamb shanks and set them on a serving platter.

To make the pan gravy, place the pot over medium heat on the stovetop. Reduce the sauce for about 10 minutes until slightly thickened. Adjust seasoning if necessary.

Serve the lamb shanks drizzled with the pomegranate-balsamic gravy, garnished with fresh pomegranate seeds and herbs.