In a large bowl, combine the all-purpose flour and salt. Add the cold, cubed unsalted butter and mix until the mixture resembles coarse crumbs. Stir in the egg yolk and cold water until the dough comes together. Wrap in plastic wrap and refrigerate for at least 30 minutes.

For the Filling

Cook the Steak

In a skillet over medium-high heat, heat the olive oil. Season the skirt steak with salt and black pepper. Add the steak to the skillet and cook for about 4-5 minutes on each side or until desired doneness. Remove from the skillet and let it rest for 5 minutes before slicing it thinly.

Sauté the Onions and Garlic

In the same skillet, add the finely chopped onion and sauté until translucent, about 3-4 minutes. Add the minced garlic, cumin, and paprika, and cook for another minute. Mix in the sliced skirt steak and chopped cilantro. Season with salt and black pepper to taste. Remove from heat and let cool.

For the Ranchero Sauce

Make the Sauce

In a saucepan over medium heat, combine the diced tomatoes, chopped onion, minced garlic, minced jalapeño, and cumin. Simmer for about 15 minutes until the vegetables are soft. Stir in lime juice, cilantro, and season with salt to taste. Remove from heat.

Assembly and Cooking

Assemble the Empanadas

Preheat your oven to 400°F (200°C). On a floured surface, roll out the chilled dough to about 1/8 inch thickness. Cut out circles using a 4-inch round cutter. Place a tablespoon of filling in the center of each circle, fold over, and crimp the edges to seal.

Bake the Empanadas

Place the empanadas on a baking sheet lined with parchment paper. Bake in the preheated oven for 20-25 minutes or until golden brown. Serve warm with ranchero sauce on the side.