Classic Bechemel Sauce:
3 tbs. butter
3 tbs. al purpose flour
pinch of salt
Milk
In a saute' pan, melt the butter and add the flour and salt. A thin paste will form. Cook the paste over medium heat for about three minutes to remove the raw-flour flavor. While whisking, slowly add milk, a little at a time. At first, the roux will get super thick. As you wisk in more milk, it will begin to thin into a rich white sauce. When it has reached the thickness you desire (it should coat a spoon that is dipped in it) add just a pinch of nutmeg. This is Bechemel Sauce, one of the 5 mother sauces. To make Mornay sauce, add grated Gruyere cheese and stir until smooth. The best way to do this is to have the cheese at room temperature. Remove the sauce from the heat source, and slowly stir in the cheese.
Many people add grated Parmesano Regiano to the Bechemel for a version of Alfredo Sauce. Very sharp cheddar is typically used for mac and cheese, or some combination of cheeses that includes very sharp cheddar.
The roux can also be used to bind soups, and is the base for Veloute Sauce, where a chicken, veal, or pork stock is added to make thin the roux into a sauce.
If you remove a roux from heat and quickly stir in raw eggs, you end up with choux paste, from which eclairs, profiteroles, and puffs are made.
Roux is a wonderful thing. You just have to keep dairy products from reaching temperatures in excess of 175' to prevent them from breaking.
Oh, and a classic example of a roux based sauce uses sausage grease and milk. Fry bulk sausage in a pan. Add 3 tbs. of flour to the sausage, along with 1/2 tsp. ground pepper. Then, after cooking for a couple of minutes, slowly stir in milk until you get a wonderful gravy. Add a bit of rubbed sage and cook for another minutes. You now have that famous southern dish, sausage gravy, which is served over biscuits.
Check out my blog for a more detailed explanation of the properties of fat, flour, and liquid.
Seeeeeeya; Goodweed of the North