Saucisson en Croute

Preheat oven to 400 degrees. Roll out pastry to a 14-by-12-inch rectangle, 1/8 inch thick. Using a pizza wheel or sharp knife, cut into one 12-by-9-inch rectangle and one 12-by-4-inch rectangle. (Reserve remaining dough, if any, for another use.)

Apply a lattice roller cutter lengthwise along the smaller rectangle, rolling firmly to cut all the way through the dough. Brush the larger rectangle with egg wash. Stretch the smaller rectangle over the larger rectangle, opening the cuts to create the lattice pattern. Using a pizza wheel, trim overhanging edges. Transfer to a baking sheet (if dough becomes too soft, freeze 15 minutes).

Flip the layered dough pieces so the lattice is on the underside. Brush one short end of the dough with egg wash. Place sausage at the other short end of the dough and roll tightly. Pinch ends to seal. Transfer to a parchment-lined baking sheet, seam-side down, and brush lattice with egg wash once more. Using the tip of a knife, cut a few steam vents in lattice.

Bake until pastry is puffed and deep golden brown, about 40 minutes. Serve warm.