Cover the ham with the mustard, place the cheese on top, shape into parcels, place each parcel on one half of the pork. Fold the other half of the pork over the parcels, press the edges together well, season, secure with toothpicks. Beat the egg. Roll the meat in the flour in batches, shake off the excess flour, dip it in the egg and then the breadcrumbs. Press the breadcrumbs down firmly so that they adhere. Heat the clarified butter in 2 non-stick frying pans. Reduce the heat, fry the cordon bleus over a medium heat for approx. 4 mins. on each side. Remove and drain on paper towels.