For the burger: Preheat the grill to high heat. Combine the veal, breadcrumbs, Parmesan, parsley, salt, pepper and eggs in a large mixing bowl and mix until everything is fully incorporated into the meat. Portion the meat into 8-ounce burgers, or into desired portions.
Grill the burgers until marked on both sides (it is not necessary to cook through as they are going to cook in the sauce), and then set aside.
For the osso bucco sauce: Heat the clarified butter in a large pot, and then saute the onions, carrots and celery until golden brown (don't be afraid to get the vegetables nice and brown). Stir in the tomato paste and cook over medium heat for 2 minutes. Pour in the wine to deglaze and bring to a simmer. Add the salt, pepper, bay leaves, rosemary and thyme and cook until the wine reduces, 5 minutes, and then pour in the stock and bring back to a slow simmer.
Add the veal burgers to the sauce, cover and cook for 45 minutes. For a thicker sauce, cook uncovered for the last 20 minutes. Serve the burgers immediately with the sauce, or let them cool completely in the sauce before refrigerating if serving at another time.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.