Preheat oven to 425°F and set rack in middle of oven. Preheat popover cups in oven about 2 minutes. Blend flour, salt, eggs, milk and butter until mixture is the consistency of heavy cream, about 1 to 2 minutes. Fill each popover cup half full with batter and bake 20 minutes.

Reduce temperature to 325°F and bake 15 to 20 minutes more.

Makes 6 popovers.