Brush six non-stick popover muffin cups (1/2-cup capacity) with vegetable oil.
In a medium sized bowl, beat eggs, flour, milk, butter, and salt until smooth.
Pour batter into cups, filling 3/4 to almost full.
Bake 40 to 45 minutes or until brown and puffy. Pierce each popover in several places with a thin wooden skewer or toothpick, and continue baking until browned and crisp, or about 5 minutes longer.
Remove from oven, remove popovers from cups and serve hot.