Season the beef shank generously with salt and pepper on all sides.

In a large, heavy-bottomed pot or Dutch oven, heat olive oil over medium-high heat. Add the beef shank and sear until browned on all sides, about 5-7 minutes. Remove the shank and set aside.

In the same pot, add the chopped onion, carrots, and celery. Sauté for about 5 minutes until the vegetables are softened.

Stir in the minced garlic and chopped wild sage, cooking for another minute until fragrant.

Pour in the balsamic vinegar and pomegranate juice, scraping the bottom of the pot to release any browned bits. Bring to a simmer.

Return the seared beef shank to the pot. Add the beef broth and fresh thyme. Bring to a gentle boil, then reduce the heat to low. Cover and let it braise for 2.5 to 3 hours, or until the meat is fork-tender.

Once the beef is cooked, remove it from the pot and cover to keep warm. Strain the braising liquid into a saucepan. If you prefer a thicker gravy, mix the cornstarch with water in a small bowl and stir it into the strained liquid. Heat over medium heat, stirring until thickened.

Slice the beef shank and serve it drizzled with the pomegranate-balsamic glaze and herb pan gravy. Garnish with fresh herbs if desired.