Break off each asparagus stalk as far down as it snaps easily. Cut off scales with a knife. Scrub with soft brush to remove all sand. Lay 1 or 2 stalks together on a cutting board; cut diagonally, making bias slices about 1″ long and ¼″ thick. You will have about 4 c.
Heat butter and water to boiling in heavy skillet with tight-fitting lid. Add asparagus and seas