Melt butter in a frypan.
Sauté onion until tender, add
witloof to pan. Cook over low heat for 3-4
minutes. Pour in stock, wine and lemon
juice. Simmer over low heat for 15-20
minutes or until tender. Remove witloof from pan with a
slotted spoon. Transfer to a greased shallow
ovenproof dish. Cover and keep warm. Rapidly boil remaining liquid
until reduced to approximately 1/2 cup. Stir in cream, mustard and
seasoning. Simmer for 4-5 minutes. Spoon cream sauce over witloof. Top with ham and parsley. Serve as a meal accompaniment.