Peach Marshmallow

A simple canned-fruit dessert from the era when a can of peaches and a bag of marshmallows counted as pantry staples. The only technical step is the thin custard sauce, and it wants patience rather than skill.

• Do not rush the sauceOne egg yolk per cup of liquid is a very light custard; over direct heat it will scramble before it thickens. Keep it over barely simmering water, stirring, until it coats a spoon at around 175-180F.
• Marshmallows melt badly aloneMarshmallows melt stiffly alone -- modern marshmallows tend to turn thick and stringy and set fast as they cool. A tablespoon of the peach syrup or water per half cup of marshmallows keeps them fluid long enough to spoon into the fruit.
• Peach juiceThis means the syrup from the can, not fresh peach puree. Peaches packed in juice or light syrup give a less cloying sauce than heavy syrup; taste before adding any sugar.
• "Flavor" the cooled custardThe original leaves this open. A half teaspoon of vanilla, or almond extract, or a spoonful of sherry per cup, added off the heat so it does not cook away.
• Cornstarch needs a real boil to lose its raw tasteCornstarch -- slake the teaspoon in a little cold syrup before it goes in, so it does not lump. With only a teaspoon to a cup in a yolk-thickened sauce, give it a couple of minutes over the water after it thickens; do not try to bring it to a boil, which would curdle the yolk.
• NutsToasted almonds or pecans, chopped coarse, and sprinkled at the table -- they soften quickly once they meet the custard.
• YieldThe recipe is written as a ratio rather than a fixed quantity: two peach halves make a portion, and the sauce is 1 teaspoon cornstarch and 1 egg yolk to each cup of syrup. Scale by the number of halves you have and make as much sauce as the drained syrup allows.