This recipe  comes form supper weekly- a great blog - you really should subscribe to it!!!
I'm stashing it here for future reference because it truly is a versatile recipe that will come in handy!
You start with 2 table spoons of butter melted in a soup pot.  Add 1/4 cup flour and whisk until smooth.  Next, add 2 cups of milk.  Once milk sauce thickens, you can add 1-2 cups of ANY kind of cheese: Parmesan, Cheddar, Monterey Jack, Pepper Jack, Provolone, Blue Cheese...  Once the cheese melts, you will have a gooey, cheesy sauce that you can pour over ANY kind of pasta, vegetable, sliced potatoes, rice, enchilada, burrito... endless possibilities!! 
 
