1. Preheat oven to 400°F.
2. Generously butter 6 cups in a popover pan or 6 six ounce custard cups.
3. In a large bowl, beat eggs well with mixer.
4. At low speed add milk.
5. Add flour and salt and beat until smooth.
6. Stir in melted butter.
7. Fill cups 1/2 full with batter.
8. Top with cheese and pour in remaining batter.
9. Bake 50 minutes or until puffed and deep golden brown.
10. Let pans cool 1 minute and then loosen with a knife.
11. Serve with hot.