From http://inthekitchenwithkath.com
(Adapted from Judith Jones’ The Pleasure of Cooking for One)
Makes 2 (Easily doubled or tripled)
1 large egg
1/3 cup milk
Pinch of salt
1/3 cup flour
Soft butter, for the custard cups*
1. Preheat the oven to 400˚. Beat the egg; add the milk, flour and salt and beat well. Butter 2 Pyrex custard cups (2 inches high, 3 1/2 inches in diameter). Be sure to butter them well! Pour the batter in the cups, and put them on a baking sheet on the middle rack in the oven. Bake for 25 minutes.
2. Remove from the oven, and remove them from the custard cups. (Now you will be really glad if you buttered them well!) Prick them all over with the tip of a sharp knife to let the steam escape.
*If you have a popover pan (I don’t), you certainly could use that. You can also use a regular muffin pan. In that case, you might have to make 3 smaller popovers.