Have all ingredients at room temperature (68 – 70 degrees f)
Position a rack in the center of the over. Preheat the oven to 450 degrees f. Grease a popover tin or standard 12-muffin pan.
Whisk together thoroughly in a large bowl:
1 cup all-purpose flour
½ teaspoon salt
Whisk together in another bowl:
2 large eggs
1 and ¼ cups milk
1 tablespoon warm melted unsalted butter
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Pour wet mixture over the flour mixture and fold just until blended. A few small lumps may remain. Fill the cups two-thirds to three-quarters full. Fill any unfilled cups one-third full with water so that the pan does not burn. Bake for 15 minutes at 450 degrees f, then reduce the oven temperature to 350 degrees f and bake for 20 minutes more, until well browned and crusty. Do not open the oven to check the popovers until the last 5 minutes to avoid deflating them. Remove from the oven, unmold onto a rack, and puncture the sides with a sharp knife to let steam escape. Serve immediately or return to a turned-off oven for up to 30 minutes for extra crispness.
Source: Joy of Cooking

