1. Sift the flour, baking powder and salt into a mixing bowl. Rub the butter and lard into the flour until fine crumbs form. Beat half the egg with 4 tbsp cold water, add to the dry ingredients and mix to form a soft dough. Wrap in clingfilm and chill for 30 minutes.
2. Preheat the oven to 180°C, gas mark 4. Heat the oil in a medium non-stick frying pan, add the onion and green pepper and cook for 3-5 minutes until soft. Add the garlic and fry for a further minute. Add the cumin, paprika and seasoning. Fry for a further minute, stirring continuously. Add the cubed salmon and toss to coat in the pan juices.
3. Roll out the pastry thinly on a lightly floured work surface. Using a saucer as a template, cut out 15 10cm rounds. Place a tablespoon of the filling on one side of the circle, brush the edge with egg, fold over and press the edges together. Brush with the remaining egg and place on a greased baking tray. Repeat for the remaining empanadas. Bake for 12-15 minutes until crisp and golden. Serve warm or cold with ketchup or tartare sauce.