Combine the flour and salt, then add the butter and rub until coarse crumbs form. Mix water, vinegar, and egg, then combine with flour mixture, kneading briefly to form dough. Chill for at least one hour.

Heat oil in a skillet, sauté onion for 5 minutes. Add chorizo and pork, cook for 15-20 minutes until browned, then cool.

Roll out dough to 3 mm thickness, cut shapes with a cookie cutter. Place filling and cheese on half, brush edges with water, seal with another cutout. Crimp edges.

Create spooky designs on pie tops, brush with egg wash if desired. Arrange on a baking tray.

Preheat oven to 375°F (190°C). Bake for 20-30 minutes until golden brown. Cool slightly before serving.