1Remove any discolored leaves and the small leaves at base of artichokes. Trim stems even with base of artichokes. Cutting straight across, slice 1 inch off tops of artichokes and discard tops. Cut off points of remaining leaves with scissors. Rinse artichokes with cold water. To prevent discoloration, plunge entire artichoke into 4 cups cold water mixed with 1 tablespoon lemon juice.
2Place steamer basket in 1/2 inch water in 4-quart Dutch oven (water should not touch bottom of basket). Place artichokes in basket. Cover tightly. Heat to boiling; reduce heat. Steam 20 to 25 minutes or until bottoms are tender when pierced with knife.
3Pluck out artichoke leaves one at a time. Dip base of leaf into melted butter.