Melt shortening in a heavy saucepan over low heat; add flour, and cook 1 minute, stirring constantly. Gradually add milk; cook over medium heat, stirring constantly, until thickened. Stir in veal, parsley, lemon juice, onion juice, and salt; chill 1 hour.
Shape veal into 6 croquettes; roll in breadcrumbs. Dip in egg; roll in breadcrumbs. Deep-fry croquettes in hot oil (375°) until golden brown.