Four Cheese Sauce

Directions

1. 1
   In a small saucepan, heat the milk until steaming, but don't let it boil or form a skin.
2. 2
   While the milk heats, melt the butter in a heavy 2-quart saucepan on low heat.
3. 3
   Add the flour and whisk to form a smooth roux.
4. 4
   Continue to cook and whisk for 3 to 4 minutes to thoroughly cook the flour.
5. 5
   Increase heat to medium, and whisk the hot milk into the roux in a thin, steady stream.
6. 6
   Continue to cook until the sauce is smooth and thickened slightly.
7. 7
   Don't stop whisking, since white sauces can burn in an instant.
8. 8
   Lower the heat, add the cheesed, mustard, and sherry, and whisk until the cheeses melt.
9. 9
   Using a double boiler or a heat diffuser, gently cook on very low heat for about 10 minutes, stirring occasionally.
10. 10
    Add salt to taste.
11. 11
    Enjoy!