Chinese Nut Sandwich

A four-ingredient sweet sandwich whose only real puzzle is what "Chinese nuts" were. Everything else is a matter of texture and proportion.

• "Chinese nuts"Almost certainly dried litchis, sold in American groceries of the period as litchi or "lychee nuts" — leathery brown shells around a raisin-like fruit with a single large stone, which is why the recipe says to stone them. Dried longan works the same way. If you buy fresh lychees instead, they are far wetter and you will need less cream, or none.
• The hinge is choppingTwo cups of stoned dried litchi is a chewy, springy mass; three tablespoons of cream will not turn it into a spread on its own. Chop or pulse the fruit fine first, then work the cream in, or the filling tears the bread when you press the top slice down.
• Thick creamHeavy cream, ideally not ultra-pasteurized, whipped only to the point of thickening. Crème fraîche or mascarpone holds better if the sandwiches must sit.
• "A little honey"Dried litchi is already sweet, so start with a teaspoon in the three tablespoons of cream and taste. A mild honey — clover, acacia — keeps the fruit's floral note; buckwheat will bury it.
• Bread and butter"Lightly buttered" does useful structural work whatever else it is for: the butter film slows the cream soaking through. Use a close-crumbed white sandwich loaf, sliced thin, and butter to the edges.
• Yield and cuttingTwo cups of filling makes roughly 8 to 10 sandwiches, or 32 to 40 small squares. Trim the crusts before cutting and press each sandwich briefly under a plate so the squares hold their shape.
• HoldingThese are tea-table food and go soft within a couple of hours. Assemble close to serving, or keep them covered with a damp towel in the refrigerator and cut at the last minute.