Preheat the oven to 400°F. Line two rimmed baking sheets with parchment paper. Roll out the puff pastry a little thinner than ⅛ inch. Cut into 12 (5-inch) squares and place them on the prepared baking sheets. Distribute 1 tablespoon chilled jam and 1 tablespoon cheese per pastry square. Leave as much of a border as possible around the filling, and then brush the border with an extremely light layer of water using your finger. Fold one side of the pastry over to form a triangle. Press down around the edges to seal it shut with your fingers. Further seal it shut by crimping it: Fold up the bottom edge and pinch, going down the edge in overlapping pleats, pinching with each one (alternatively, use the back of a fork to crimp it shut). Use scissors or a paring knife to make a tiny slit in the top, but don’t pierce through to the bottom. Brush with the beaten egg yolk. Glaze them with more jam that’s been briefly warmed in the microwave. Bake for 20 minutes, until golden brown, with one or two badly sealed ones oozing juices. Let cool for 20 minutes.

Excerpted from A Dish for All Seasons by Kathryn Pauline c 2022. Published by Chronicle Books.