Beat the eggs in a medium mixing bowl with an electric beater until foamy.
Add the milk and continue beating. Add the butter and flour and continue to beat until smooth.
Place 1 TBS of the popover batter in the bottom of each of 12 oiled muffin or custard cups.
Sprinkle a teaspoon of the grated cheese into each cup. Top with the remaining batter, but do not fill the cups more than two-thirds full.
Bake for 40 to 45 minutes, until puffed and golden brown. Do not open the oven sooner than 5 minutes before the popovers are finished baking, or they may fail to puff.