To make, place butter (or margarine, though it won’t taste as good) in pan and set pan in a 425° oven until butter is melted and foamy. Meanwhile, quickly mix batter. In blender or food processor, whirl eggs at high speed for 1 minute; with motor running, gradually pour in milk, then slowly add flour. Continue whirling for 30 more seconds. Or, in a bowl, beat eggs until blended; gradually beat in milk, then flour. Remove pan from oven (butter should be foamy), then pour in batter. Return pan to oven and bake for 20 to 25 minutes (time depends on pan size), or until puffy and well browned. Serve immediately.
To serve as a sweet breakfast pancake, dust with nutmeg, if desired, then cut into wedges and serve with powdered sugar, fruit, hot fruit, canned pie filling or syrup.