In a mixing bowl, combine turkey, eggs, bread crumbs, black garlic, and salt and pepper. Combine until everything is well incorporated, but do not overmix. (Tip: test the seasoning by steaming a small portion and adjusted if needed.)
Form meatballs into 3 oz portions.
Stuff each portion with a cube of cheese and roll the meatball.
Chill until firm.
In a steamer or covered sauté pan with a wire rack, steam the meatballs for about 6-8 minutes to cook half way.
Saute the meatballs in olive oil until brown on outside. Check for doneness.
To serve, place meatballs in bowl, top with green peppercorn sauce and slices of prosciutto.
Green Peppercorn Sauce
Sweat shallot over medium heat until soft. Deglaze pan with cognac (or brandy) and reduce until almost gone.
Add heavy cream and peppercorns and reduce until you have a good, sauce-like texture. Add slt and pepper to taste.