Bechamel is one of the mother sauces of classical French cooking. Simply butter, flour, milk and a bit of salt and pepper, it's elegant but not always easy to get right. It's often included in lasagna and pastitsio as is, but the French usually modify it in some way. Adding cheese produces Mornay Sauce, adding crawfish, shrimp or crab turns it into a Nantua sauce, Soubise features onions sweated in butter, and by grating in some fresh nutmeg and by substituting cream for the milk it shifts into a cream sauce .
The trick to these sauces is that the flour and butter (or any other fat) are whisked together over low heat for about five minutes (don't leave it's side). The flour/butter mixture is known as a roux. This step coats the starch granules in the oils so they don't clump together and also cooks the flour so it no longer tastes raw. The flour and butter should be equal weights, but equal quantities also work up to about 1/4 cup of each. The amount of milk determines how thick the sauce is - figure a cup of milk for each 2 tablespoons of butter and flour. So two cups of Bechamel would be 4 tablespoons butter, 4 tablespoons flour, and 2 cups milk. Gradually bring the sauce to a boil over medium-high heat, stirring constantly to prevent burning, for maximum thickening. As soon as it boils, pull it off the heat. (Note: I usually heat the milk - or stock - in the microwave before adding it to speed up the thickening process.)
At this point, you can add other flavorings such as salt, ground white pepper, perhaps some dried mustard, some finely chopped crawfish or lobster, sweated onions. Let your imagination run free.
You don't have to stick with either butter for the fat or milk for the liquid. Fry up some crumbled breakfast sausage, sprinkle it with flour when it's nearly done, and add milk 5 minutes later to make sawmill gravy for biscuits.
Or start with butter and flour, but replace the milk with shrimp stock for a particularly rich Nantua sauce. And of course you can make a wonderful Mornay sauce by just adding some gruyere, cheddar, Manchego or other cheese. (If you're adding cheese, use a bit more liquid to produce a thinner base sauce, the cheese will thicken it up.)
Makes 1 cup
2 tablespoons unsalted butter
2 tablespoons all-purpose flour
1 cup hot milk (zap in microwave on high for 1 minute)
1/4 teaspoon dried mustard
Salt and ground white pepper to taste
Melt butter in a heavy saucepan over low heat. Whisk in flour and cook for 4 - 5 minutes, whisking frequently.
Whisk in hot milk and increase heat to medium-high. Continue stirring almost constantly until sauce thickens and begins to bubble.
Remove from heat and season with mustard, salt and pepper. (Note: white pepper is used because it's milder than black pepper and can't be seen in the sauce. Black pepper is perfectly acceptable.)
1 recipe basic béchamel plus 1/2 cup additional milk
1 cup shredded cheese
Make basic sauce, remove from heat, and whisk in cheese until completely melted.
This is great served over steamed broccoli or cauliflower.
1 recipe basic béchamel
1/4 cup cooked, very finely chopped crawfish, shrimp, crab or lobster.
1/4 teaspoon hot paprika
Make basic sauce, remove from heat, and whisk in shellfish and paprika.
I love this sauce on pasta and substitute 1/2 cup white wine for 1/2 cup of the milk. It has a lovely pink color.
1/4 lb. crumbled breakfast sausage (use mild if you must, but hot works better)
2 tablespoons all-purpose flour
1 cup hot milk (zap in wicrowave on high for 1 minute)
Cook sausage in skillet over medium heat until it has rendered most of its fat and is nicely browned. Us a slotted spoon to transfer sausage to a plate lined with a paper towel.
Return skillet to heat and whisk in flour. Cook 3 minutes whisking frequently.
Whisk in milk, cook until thickened then add sausage. Serve over hot biscuits. This gravy will even make refrigerator biscuits edible.