With the rack in the middle position, preheat the oven to 350°F (180°C).
In a large pot, brown the shanks in half the butter. Season with salt and pepper. Add the mustard seeds and cook for 2 minutes. Set the meat aside on a plate.
In the same pot, cook the vegetables in the remaining butter. Season with salt and pepper. Sprinkle with the flour and add the Dijon mustard. Stir to combine. Deglaze with the wine and bring to a boil, stirring constantly. Add the broth and return the meat to the pot. Bring to a boil.
Cover and bake for 2 hours. Uncover and continue baking, turning the shanks occasionally, for about 1 hour or until the meat falls easily from the bone. Serve with mashed potatoes and a green lettuce and mustard shoots salad.
If desired, remove the shanks from the sauce at the end of cooking and let the sauce reduce to a syrupy consistency.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.