Remove asparagus from can, steam with ½ cup soup stock for 15 minutes, drain dry, and arrange on one side of serving plate.
Remove old leaves from mustard plants, keeping the stem part. Slice into pieces, scald in boiling water for 5 seconds, then soak in cold water, drain dry. Stir-fry mustard in 3 tablespoons oil, add 1 cup soup stock, and season with ½ teasp