Traditionally, Milanese ossobuco is served with a flavorful sauce called gremolata. Gremolata is a combination of minced garlic, lemon zest, and parsley, which is sprinkled on top of the ossobuco just before serving to enhance its flavors. However, if you are looking to add a different sauce to your Milanese ossobuco, it's ultimately a matter of personal preference. While it may deviate from the traditional preparation, experimenting with sauces can be a fun way to create new flavors and customize the dish to your liking. Just keep in mind that the flavors of the sauce should complement the rich and tender meat of the ossobuco.