Pistachio Bisque

This is a built-on recipe: it assumes you already have the book's Pistachio Ice Cream churned and still soft. The measurements suit roughly a quart of that base.

• "Bisque" hereIn American frozen-dessert vocabulary of the period, a bisque is an ice cream loaded with pounded macaroons or nuts, nothing to do with soup. Expect a granular, chewy texture rather than a smooth one.
• The macaroonsMacaroons of this period are the hard almond kind, crushed, not soft coconut macaroons or French macarons. Amaretti are the closest thing on a shop shelf; crush enough to fill half a cup.
• Fold, do not churnAdd the macaroons and nuts when the ice cream is the texture of soft-serve, then stop working it. Running the machine after they go in pulverises the macaroons into paste and the mixture turns muddy.
• Chill the additionsCold nuts and crumbs keep the base from slumping. Spread them on a tray in the freezer for fifteen minutes before folding in.
• Peanuts and almondsUse unsalted roasted peanuts with the skins rubbed off, and blanched almonds. Salted cocktail peanuts throw the whole thing off balance.
• Moulding"Mould" here means packing the mixture into a shaped mould (brick or melon shapes were usual), sealing the join -- buttered paper was the common dodge -- and burying it in ice and rock salt for a couple of hours. A loaf pan lined with parchment and pressed with plastic wrap directly on the surface, then four hours in the freezer, does the same job.
• Slicing and servingLet the mould stand at room temperature five minutes, dip it briefly in warm water, and turn it out. Cut in thick slices with a hot dry knife. The recipe gives no quantity for the base, but the added bulk stretches whatever you start with by a serving or two.
• Claret sauceThe book's sauce is a sweetened red-wine syrup. It is genuinely optional, as the recipe itself says ("with or without"); the nuts and macaroons already carry the dish.