Canned String Bean Salad

A cold marinated bean salad from a period when canned vegetables were a year-round staple and "French dressing" still meant oil and vinegar. Two details need translation: the can size and the dressing.

• No. 2 canA No. 2 can holds about 20 fluid ounces, roughly 2.5 cups; the drained beans come to somewhat less, on the order of 14 oz. A standard 14.5 oz supermarket can is smaller, so use one and a half cans, or about 12 oz of blanched fresh green beans, per batch of seasonings listed.
• French dressingIn American cookbooks of this era French dressing is a plain vinaigrette: roughly three parts oil to one part vinegar, with salt and pepper, shaken before use. It is not the sweet orange bottled product sold under that name today, which would overwhelm the beans.
• Ice boxRefrigerate. An hour is the minimum; two to three hours is better, and the salad holds well overnight.
• Rinse before marinatingCanned beans carry a good deal of packing salt and a faint tinny note. Draining and a quick rinse, then patting dry, gives the dressing something to cling to and lets you control the seasoning at the end.
• The onionOne whole minced raw onion in a can of beans is assertive by current taste. A small shallot or a few tablespoons of minced red onion, soaked briefly in cold water to take off the bite, is a milder alternative.
• MustardA 'dash mustard' here is most likely dry mustard powder, whisked into the dressing rather than sprinkled on the beans -- about a quarter teaspoon per half cup of dressing -- though prepared mustard would also fit the period.
• Season lastSalt after the marinating, not before. The canned beans, the dressing and the celery all contribute salt, and the amount needed is only clear once the beans have taken up the dressing.
• YieldEnough for four as a side salad, six as part of a larger cold plate.