In a large mixing bowl, whisk together the all-purpose flour and sea salt. Cut in the chilled unsalted butter until the mixture resembles coarse crumbs. Gradually add the chilled water, egg, and apple cider vinegar, mixing until a dough forms. Wrap the dough in plastic wrap and refrigerate for at least 1 hour.

Heat a tablespoon of oil in a skillet over medium heat. Add chopped onions and sauté until soft. Stir in the ground chorizo and minced pork, breaking up the meat. Cook for 15-20 minutes until fully browned. Mix in paprika, minced garlic, and cayenne pepper. Remove from heat and let cool.

Preheat your oven to 375°F (190°C). Roll out the dough to about 3mm thick. Use pumpkin-shaped cookie cutters to cut out half of the shapes. Place a spoonful of filling on each cut-out, sprinkle with cheeses, moisten edges with water, and top with another cut-out. Seal edges by crimping with a fork.

Line a baking sheet with parchment paper. Place assembled hand pies on it, brushing tops with egg wash. Bake for 20-30 minutes or until golden brown and flaky. Keep an eye on them.

Once baked, remove from oven and let cool on a wire rack for about 5 minutes. Serve warm and enjoy the combination of crispy pastry and zesty filling.