Pour milk into small bowl of electric mixer;
sift in flour and salt.
Beat at medium speed until batter is smooth,
about 1 1/2 min., scraping bowl frequently.
Add butter and eggs;
beat to mix thoroughly, about 1 min.
(Avoid overbeating; it reduces volume.)

Ladle batter into well-greased custard cups,
filling cups half full.
Place cups on baking sheet and place on rack
in center of hot oven (400°).
Bake in hot oven about 40 min.
Keep oven door closed until about 5-10 min.
before end of baking time or popovers may collapse.

Remove popovers from oven,
prick sides with kitchen fork to permit steam to escape.
Lay popovers on their sides in custard cups
and return to oven, heat turned off
and door left ajar, for 5 min. to dry inside.
Makes 7 popovers bakes in 5 oz. custard cups.