Braised Lamb Shanks with Herb Infusion

Recipe
Ingredients:

4 lamb shanks
2 tablespoons olive oil
2 onions, finely chopped
3 cloves garlic, minced
1 carrot, diced
2 celery stalks, diced
1 cup beef broth (additional for sauce if needed)
2 cups beef broth
1 can (14 oz) diced tomatoes
2 tablespoons tomato paste
1 teaspoon fresh thyme leaves
1 teaspoon fresh rosemary, chopped
Salt and pepper to taste