In a large bowl combine the flour and salt. Add the cold cubed butter and use a pastry cutter or your fingertips to cut the butter into the flour until mixture resembles coarse crumbs with pea-sized pieces of butter remaining.

Whisk the egg yolk into the ice water. Gradually drizzle the egg-water into the flour-butter mixture, mixing gently with a fork until the dough just comes together. You may not need all the water. Dough should be moist but not sticky.

Gather the dough into a ball, flatten into a disk, wrap in plastic, and refrigerate for at least 30 minutes (up to 2 hours) to rest and firm the butter.

Beef Filling

Prepare vegetables

Heat 1 tablespoon vegetable oil in a large skillet over medium heat. Add the diced carrot and potato and sauté 6–8 minutes until beginning to soften. Remove from the pan and set aside.

Add the remaining 1 tablespoon oil to the skillet. Add the chopped onion and cook 4–5 minutes until translucent. Stir in the minced garlic and cook 30 seconds until fragrant.

Increase heat to medium-high and add the ground beef. Break it up with a spatula and brown until no pink remains (about 6–8 minutes). Drain excess fat if the beef is very greasy, leaving a tablespoon to carry flavor.

Return the sautéed carrot and potato to the pan with the beef. Stir in the tomato paste and cook 1–2 minutes to remove raw flavor. Add the beef broth, soy sauce, brown sugar, cumin, and smoked paprika. Stir to combine and bring to a simmer.

Reduce heat to medium-low and simmer 6–8 minutes until the liquid reduces and the mixture thickens. Stir in the green peas and continue cooking 2–3 minutes until peas are heated through. Taste and season with salt and black pepper as needed.

Remove pan from heat and let the filling cool for 10 minutes. Fold in chopped hard-boiled eggs if using. The filling should be thick and not watery to avoid soggy dough.

Assembly & Baking

Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper.

On a lightly floured surface, roll the chilled dough disk to about 1/8-inch (3 mm) thickness. Using a 6–7 inch round cutter or a bowl, cut out circles for the pastel (yields about 8–10 rounds). Re-roll scraps as needed.

Place about 2–3 tablespoons of the cooled beef filling in the center of each dough circle, leaving a 1/2-inch border. Brush the border with a little beaten egg or water. Fold the dough over to form a half-moon and press edges to seal. Crimp edges with a fork to ensure a tight seal.

Arrange assembled pastels on the prepared baking sheet. Beat the remaining whole egg with 1 teaspoon water to make an egg wash and brush each pastel lightly to gloss and brown them in the oven.

Bake in the preheated oven 18–22 minutes, until golden brown and crisp. Remove from oven and cool 5 minutes on the baking sheet before transferring to a wire rack.

Serve warm. Pastel can be reheated in a 350°F (175°C) oven for 8–10 minutes to crisp before serving.