To make the dough, combine the flour, salt, sugar, and baking powder in a large bowl until the mixture resembles large crumbs.
In a separate bowl, beat the eggs and milk together.
Gradually add the egg mixture to the flour mixture, stirring until a soft dough forms.
Knead the dough on a floured surface until smooth, then cover with plastic wrap and let it rest in the fridge for at least 30 minutes.
To make the filling, heat the oil in a large skillet over medium-high heat. Add the beef and cook until browned on all sides.
Add the onions, garlic, cumin, oregano, and paprika, and cook until the onions are soft.
Add the parsley, peas, carrots, potatoes, aji Amarillo paste, chicken broth, salt, and pepper, stirring well.
Lower the heat, cover the skillet, and let the mixture simmer for 15-20 minutes or until the vegetables are cooked and the broth has evaporated.
Preheat your oven to 400°F.
Take the dough out of the fridge and divide it into 12-15 equal portions. Roll out each portion into a circle of about 6 inches in diameter.
Place a spoonful of the filling in the center of each circle, making sure to leave enough space around the edges to seal the pastry.
Brush the edges with water and fold the circle in half, pressing the edges together to seal them.
Use your fingers to pinch and crimp the edges of the pastry together to create a rope-like edge.
Place the salteñas on a baking sheet lined with parchment paper and brush the tops with beaten egg to give them a shiny finish.
Bake for 25-30 minutes or until the salteñas are golden brown and crispy. Serve hot.