Remove the chorizo from the casing and add to a mixing bowl with the beef mince, onion, coriander, parsley, smoked paprika, cumin and chilli flakes. Mix everything together then place into a frying pan over medium heat and cook for 2 minutes. Add the tomato paste and cook for a further 5 minutes or until everything is cooked through. Remove the pan from the heat and let the mixture cool before storing in a container in the fridge overnight. This intensifies the flavour.
Add the flour to a bowl and add in the butter, begin to rub the butter and flour with your fingertips until a breadcrumb-like consistency. Add the egg and water, bring together then turn out onto a floured surface and begin to knead until soft and smooth. Cover with glad wrap and place into the fridge to rest for 20 minutes. When ready to use, divide the dough into four even portions and roll out each portion into a thin sheet. Use a cookie cutter to cut out discs. Use immediately or store in the fridge cover in glad wrap.
Wet the edges of the dough and pinch both sides up, place in some filling and then fold in half and seal the edges. Start at one end and begin to braid by folding one triangle of dough over itself, press to seal stretch that part of the dough of the dough a bit and continue to fold over the top, pressing to seal.
Place onto a lined baking tray and brush with egg wash, place into a preheated oven and bake for 20 minutes. When the empanadas are ready, remove from the oven and let cool for 5 minutes.
Can be frozen, place on a lined baking tray and cover with plastic. Place into the freezer until frozen then place into an airtight container/ziplock bag for up to 3 months.