String Beans with Cream Sauce

A plain white-sauce treatment for green beans, written for cooks who already knew how to boil them. The proportions are a standard thin bechamel, and the whole thing comes together in the time the beans take to drain.

• The measurementsHalf a pint is one cup (240 ml). The recipe's "a tablespoonful of butter and flour" is ambiguous, but it is normally read as a tablespoon of each; that will thicken a cup of milk to a pouring sauce rather than a coating one. Use two of each if you want it to cling.
• Butter and flour, uncookedRubbing raw butter and flour together makes a beurre manie, which is whisked into liquid rather than cooked first. Because the flour is never toasted, the sauce must actually reach a boil and hold there a minute or two, or it will taste of raw starch.
• Bringing it to a boilThis is the hinge. The instruction to boil is not carelessness — it is what sets the flour. Stir constantly from the moment the sauce goes into the pan so the beans do not catch on the bottom.
• Cook the beans less than the book intendsCook the beans less than older instructions suggest -- Boiled string beans in period cookbooks often ran twenty minutes or more. Five to eight minutes in well-salted water gives beans that still have some bite, which matters more here because they get a second turn on the heat in the sauce.
• Dry the beansDrain thoroughly and let them steam dry in the hot pan for a few seconds. Water clinging to the beans will thin the sauce and make it taste flat.
• Cream or milkThe recipe allows either. Whole milk gives a lighter sauce; cream will need a little more liquid or it will turn heavy and dull the beans. Half-and-half is a reasonable middle.
• SeasoningNutmeg is the traditional partner to a milk sauce and should be barely detectable — a few strokes on a grater. Paprika and cayenne are alternatives, not additions; choose one.
• YieldThe recipe gives no quantity of beans; a pound with a cup of sauce would serve about four as a side dish.