Self Saucing Asparagus.

Break off the woody end of the stalks and discard.
Pack the spears into the bottom of a saucepan and half cover with boiling water - put on hob and steam until cooked.
Remove the spears and keep warm.
Add a knob of butter and a dash of Sherry vinegar (balsamic also works well) to the water and boil to reduce.
When it is a sauce like syrup poor over the spears and serve.