How to Make It
In a very large skillet, melt 4 tablespoons of the butter in 1/4 cup of the lard. Add the diced beef, season with a generous pinch each of salt and pepper and cook over high heat, stirring occasionally, until browned and any liquid has evaporated, about 8 minutes. Transfer to a large bowl, pouring any fat in the skillet over the beef.
In the same skillet, melt the remaining 2 tablespoons of butter in the remaining 2 tablespoons of lard. Add the onion, bay leaves and a generous pinch each of salt and pepper and cook over moderate heat, stirring, until the onion is soft and golden, 10 minutes. Discard the bay leaves. Scrape the onion and any fat over the meat and let cool slightly. Stir in the scallions, cumin and red pepper; season with salt and black pepper. Refrigerate overnight.
In a small saucepan, bring the water, butter and salt to a simmer. When the butter is melted, pour the mixture into a large bowl and let cool to room temperature. Add the flour and stir until the dough comes together. On a lightly floured work surface, gently knead the dough until almost smooth but still slightly tacky with some streaks of butter. Divide the dough into two pieces, wrap them in plastic and refrigerate until firm, at least 1 hour or overnight.
Preheat the oven to 400° and oil 2 large baking sheets. Work with 1 piece of dough at a time: On a generously floured work surface, roll out the dough 1/8 inch thick. Using a 5-inch round plate as a guide, cut out 8 rounds of dough. Moisten the edge of the dough rounds with water. Mound 1 1/2 packed tablespoons of the beef filling on one half of each round and fold the dough over to form half moons; press the edges to seal. Pinch the edges at intervals to make pleats or crimp with the tines of a fork. Repeat with the remaining piece of dough to form 8 more empanadas.
Place the empanadas on the baking sheets and bake in the upper and lower thirds of the oven for 35 minutes, shifting the pans once halfway through, until browned. Serve the empanadas warm or at room temperature.
The baked empanadas can be refrigerated overnight. Reheat in a 350° oven.
Rendered lard is available at farmers’ markets and specialty butcher shops.