Store-bought puff pastry, rolled into 1 (10 by 12-inch) rectangle
Prepare the egg wash: Combine the yolks, whole egg, and milk in a small mixing bowl and whip with a hand whisk until well combined. Preheat the oven to 400 degrees. Set the puff pastry on a lightly floured work surface, with the long side facing you and cut in half from top to bottom. Use a pastry brush to coat one piece of the dough with egg wash. Lay the olives spaced about 1-inch apart from top to bottom on the egg-washed dough. Place the other rolled-out dough half on top of the olives and mark each olive by pressing the dough on either side of the olive. Use a sharp paring knife to cut between each puff pastry-covered olive. Place on a parchment paper-covered baking sheet and brush with more egg wash. Bake until well risen and golden brown, about 20 minutes. Cool completely on a wire rack before serving. There is no need to cut these in half. Just cut between the olives to make small packages. Baking and cooling is the same. These puff pastry items are best eaten the day they are made.