Ham Napoleons

A two-part assembly that assumes you already have a ham mousse on hand, as the book's other pages supply. The pastry work is the part that decides whether these hold up on a plate.

• Puff paste temperatureThe recipe names no oven. Modern practice for thin puff sheets is 400-425F until fully dry and browned, roughly 15-20 minutes depending on how thin they are rolled. A cooler oven leaves the interior damp and the layers collapse under the mousse.
• Weight the sheetsFor flat, even slabs that stack, dock the rolled paste all over with a fork and bake it between two heavy sheet pans, or under a wire rack. Free-risen puff domes and will not cut into tidy rectangles.
• Cut warm, not coldThe instruction to use a very sharp knife is the hinge here. Trim while the pastry is still slightly warm, with a long serrated blade and a sawing motion; once cold and brittle it shatters rather than cuts.
• Ham mousseIn books of this period this usually means finely ground cooked ham bound with a little gelatin and folded with whipped cream, chilled until set, though hot baked versions also appear under the same name. For this use it must be cold and firm enough to hold a knife-edge, or the layers slide apart.
• Assemble latePastry against moist mousse softens within the hour. Cut, chill, and fill no more than 30 minutes before serving, and keep them refrigerated until they go out.
• The sauceNo sauce is named. A thin mustard cream, a mild horseradish sauce, or a warm Madeira-scented brown sauce all suit; spoon it onto the plate rather than over the pastry.
• YieldA single sheet of paste rolled to about 12x16 inches gives roughly 32 pieces of 2x3 inches after trimming, which is about 16 finished napoleons at entree size, or more if you cut the rectangles smaller for appetizers.