Trim the Lamb Shank (4). Rinse lamb shanks under running water. Dry them thoroughly with paper towels.
Mix Kosher Salt (2 teaspoon), Ground Black Pepper (1/2 teaspoon), and Granulated Sugar (1 teaspoon) in a small bowl.
Massage the lamb shanks with the salt-pepper-sugar mixture, making sure to coat all sides.
Place lamb shanks in a Dutch oven (or a heavy bottom pan with a lid) on a single layer.
Cover and cook in low heat, turning shanks once or twice, until meat is fork-tender and almost falling off the bone. This takes around 2 ½ to 3 hours.
Take 2 to 3 tablespoons of the liquid in the pan and stir it together with Dijon Mustard (1 tablespoon) and Lemon Juice (1 1/2 tablespoon).
Spoon it over the lamb shanks. Turn the heat off and let it marinate for 10 minutes.
Finely chop the Italian Flat-Leaf Parsley (1/2 cup). Zest the Lemon (1). Mince the Garlic (2 clove).
To make the Gremolata, combine finely chopped Italian parsley, minced garlic and lemon zest in a bowl.
When ready to serve, garnish each lamb shanks with a tablespoon of gremolata and Parmesan Polenta (to taste).