Always works for me:
melt 2T butter over medium heat. add 2T flour. stir well and cook a few minutes. slowly stir in 1 cup milk (if it gets lumpy, simply whisk a moment). when milk is fully incorporated, turn up heat and bring to a boil while stirring constantly. You can adjust the quantity of butter and flour up or down if you want a thicker or thinner sauce.
If you need another option, I like Ina Garten's recipe from her mushroom lasagna - it's very rich and delicious. I like the addition of the nutmeg as well. It makes a lot too! I cook the flour/butter mixture a bit longer than she recommends (she recommends 1 minute, I keep it going for a few) because I find it to work out better in the end and it doesn't taste as flour-y. Also her recipe says 3-5 minutes for it to thicken but I find it takes closer to 8-10 minutes to get it to a really nice thick consistency.
4 cups whole milk
I stick butter
1/2 cup all-purpose flour
1 tablespoon salt (or to taste)
1 teaspoon freshly ground black pepper (or to taste)
1 teaspoon ground nutmeg
Warm the milk and set aside. Melt butter in a large saucepan. Add the flour and cook for a couple minutes over low heat. Dump the milk into the butter/flour mixture all at once – it will seem a bit scary but it’s fine. Add 1 tablespoon salt, the pepper, and nutmeg, and cook over medium-low heat, stirring first with the wooden spoon and then with a whisk, for 3 to 5 minutes, until thick. Set aside off the heat.
The general thing is to keep the milk warm ( I just warm it up in the microwave). At least that's what keeps my bechamel from being lumpy but even if it has lumps you can easily strain them out.
You asked a simple question and I'm not sure if you want the simplest answer. It depends on what you're going to use the bechamel for.
Gourmanda's directions are for a simple basic light bechamel which you can flavor as you choose. By adjusting the amount of flour and butter, you can make a heavy bechamel, suitable for a soufflé. By adding even more flour, you can make binding bechamel for making something like croquettes. By substituting cream for the milk, you'll have an enriching bechamel. Basic cookbooks like the Joy of Cooking or Bittman's How to Cook Everything have good guides.
This is one of the "mother sauces" and once you conquer this, you'll be able to make lots of things with little difficulty. Expanding on it becomes easy. Substitute stock for the milk, and you've got a velouté, and as you vary the additions you can make dozens and dozens of fancy sauces.
One trick that works for me when I use the same recipe and basic method that Gourmanda recommends is to pull the pot off the heat when I begin to add the milk. I add just a little and then stir it in well before adding the rest slowly. I find it combines more smoothly without getting lumpy.
I learned this no-fail Bechamel Sauce at le Cordon Bleu in Paris. It comes out perfectly every time.
According to the thickness you want your sauce to be:
In a heavy saucepan ( I use le Creuset) on a low flame melt 1, 2, or 3 Tbs unsalted Butter
Whisk in 1, 2, or 3 Tbs Flour
Cook for 1, 2, or 3 minutes DO NOT LET FLOUR BROWN
Whisk in 1 cup of cold or room temp milk all at once . DO NOT HEAT THE MILK. Heating the milk causes the protein to coagulate and will give you a lumpy sauce.
Cook over low flame and keep whisking until the sauce starts to thicken. Remove from heat when the Sauce reached desired thickness.
Whisk in desired seasoning to taste, salt, white pepper, nutmeg.
If it is going to stand for a while, place Saran Wrap directly on surface of the Sauce to prevent a skin from forming. You can also take a piece of cold Butter and rub it over the surface to seal out the air.
Yes, Diana. For a thin sauce, use 1 TBS butter, 1 TBS flour , 1 cup whole milk.
For a medium sauce, use 2 TBS butter, 2 TBS flour , 1 cup whole milk
For a thick sauce, use 3 TBS butter, 3 TBS flour , 1 cup whole milk
If you are making a veloute sauce using chicken stock or fish stock, the stock can be heated before adding to the roux.
I always heated my milk (per recipe instructions) and often had to work hard to get the lumps out.
Then absent-mindedly watching Emeril one day, he said "Always use cold liquid. Cold into hot means no lumps."
I tried it and it works. Just pour slowly and gradually and stir. I don't let the sauce boil, just gently simmer (surface just moving quietly).
I love adding nutmeg and bay leaves for a piquant Bechamel.
re: toodie jane
I'm with you and Emeril on this. In addition to using cold liquid (milk or stock), I pull the roux from the heat when I make the first addition of liquid. Once I get that incorporated, I can turn the flame back on under the pot for the rest of the liquid addition. I never have problems with lumps.
I also don't use a whisk, preferring a flat-edged wooden spatula to scrape the bottom and corners of the pan well.
Strange how different methods works for everyone. Only trial and errors will let you know what works for you.