Kitchen twine, for bouquet garni and tying the veal shanks
3 whole veal shanks (about 1 pound per shank), trimmed
Sea salt and freshly ground black pepper
All purpose flour, for dredging
1/2 cup vegetable oil
1 small onion, diced into 1/2-inch cubes
1 small carrot, diced into 1/2-inch cubes
1 stalk celery, diced into 1/2 inch cubes
1 tablespoon tomato paste
1 cup dry white wine
3 cups chicken stock
3 tablespoons fresh flat-leaf Italian parsley, chopped
1 tablespoon lemon zest
Place the rosemary, thyme, bay leaf and cloves into cheesecloth and secure with twine. This will be your bouquet garni.
For the veal shanks, pat dry with paper towels to remove any excess moisture. Veal shanks will brown better when they are dry. Secure the meat to the bone with the kitchen twine. Season each shank with salt and freshly ground pepper. Dredge the shanks in flour, shaking off excess.
In a large Dutch oven pot, heat vegetable oil until smoking. Add tied veal shanks to the hot pan and brown all sides, about 3 minutes per side. Remove browned shanks and reserve.
In the same pot, add the onion, carrot and celery. Season with salt at this point to help draw out the moisture from the vegetables. Saute until soft and translucent, about 8 minutes. Add the tomato paste and mix well. Return browned shanks to the pan and add the white wine and reduce liquid by half, about 5 minutes. Add the bouquet garni and 2 cups of the chicken stock and bring to a boil. Reduce heat to low, cover pan and simmer for about 1 1/2 hours or until the meat is falling off the bone. Check every 15 minutes, turning shanks and adding more chicken stock as necessary. The level of cooking liquid should always be about 3/4 the way up the shank.
Carefully remove the cooked shanks from the pot and place in decorative serving platter. Cut off the kitchen twine and discard.
Remove and discard bouquet garni from the pot.
Pour all the juices and sauce from the pot over the shanks. Garnish with chopped parsley and lemon zest.
Peel the potatoes and cut into 1/2-inch dice. Place in a medium saucepan and cover with cold water. Set over high heat, cover and bring to a boil. Once boiling, uncover, decrease the heat to maintain a simmer and cook until tender and easily crushed with tongs, approximately 10 to 15 minutes. Place the half-and-half and butter into a microwave-safe container and heat in the microwave until warmed through, about 35 seconds. Drain the potatoes in a colander and then return to the saucepan. Mash the potatoes and then add the half and half, butter, salt and pepper and continue to mash until smooth. Stir in the yolk until well combined.
Preheat the oven to 400 degrees F.
While the potatoes are cooking, prepare the filling. Place the canola oil into a 12-inch saute pan and set over medium high heat. Once the oil shimmers, add the onion and carrots and saute just until they begin to take on color, approximately 3 to 4 minutes. Add the garlic and stir to combine. Add the lamb, salt and pepper and cook until browned and cooked through, approximately 3 minutes. Sprinkle the meat with the flour and toss to coat, continuing to cook for another minute. Add the tomato paste, chicken broth, Worcestershire, rosemary, thyme, and stir to combine. Bring to a boil, reduce the heat to low, cover and simmer slowly 10 to 12 minutes or until the sauce is thickened slightly.
Add the corn and peas to the lamb mixture and spread evenly into an 11 by 7-inch glass baking dish. Top with the mashed potatoes, starting around the edges to create a seal to prevent the mixture from bubbling up and smooth with a rubber spatula. Place on a parchment lined half sheet pan on the middle rack of the oven and bake for 25 minutes or just until the potatoes begin to brown. Remove to a cooling rack for at least 15 minutes before serving.