In a cup, combine the dressing and mustard and chill. Place the asparagus in a shallow bowl and spoon enough French dressing over to cover. Cover and chill for 4 hours.
Lay the smoked ham on a work surface and spread an even layer of the salad dressing-mustard mixture on each slice. Lay an asparagus spear on each slice of ham and roll into a tight roll. Chill for 1 hour before serving.
Serve the rolls with the mustard dressing on the side.