In a food processor grind up the stuffing cubes until they form bread crumbs, set aside.
On a clean work surface area get 3 shallow dishes. Pour the flour into the first one, the beaten egg, milk and Dijon mustard in the next, and the seasoned stuffing bread crumbs in the last.
Season the cutlets with salt and pepper on both sides and turn lightly into the flour. Next coat the cutlets in egg-mustard mixture and then into the stuffing breadcrumb. Coat both sides, then set aside until all 8 are coated.