1. Preheat the oven to 450°. Generously butter a popover pan or 2 mini-muffin pans. In a medium bowl, whisk the milk with the flour and salt; there will be some lumps. Add the eggs and butter and whisk just until blended.
2. Heat the prepared pan or pans in the oven until the butter is sizzling, about 1 minute. Carefully spoon the popover batter into the pan or pans: Fill the popover pan two-thirds full for giant popovers or fill the mini-muffin pans three-quarters full for mini popovers. Bake the popovers for 15 minutes without opening the oven, then lower the temperature to 350° and bake the minis 15 minutes longer, or the giants 20 minutes longer. Transfer the popovers to a baking sheet, poke a small hole in the tops with a tooth-pick and then dry them out in the oven for another 10 minutes. Serve the popovers warm.
Serve With: Shrimp salad or sweet butter and jam.