Grill the marrows in lengthwise strips, set aside, and meanwhile cut gbejna in 1 cm strips. On every slice of veal, lay a slice of ham, a strip of grilled marrow and three strips of gbejna, season and roll, tucking in both ends. Prepare and egg wash by combining the two eggs and milk. Dust the involtini in flour, than egg wash them and transfer them to the seasoned breadcrumbs, and set aside. Heat a frying pan with a knob of butter and a drizzle of oil, and shallow fry the croquettes until golden brown. Transfer all the fried veal on an oven proof dish and bake for a further 15 minutes. ( This will seep out all excessive oil)