In a large bowl, whisk together the all-purpose flour, turmeric powder, and salt. Cut in the cold, cubed butter using a pastry blender or your fingers until the mixture resembles coarse crumbs.

Gradually stir in the ice water, 1 tablespoon at a time, until the dough just begins to come together. Form the dough into a disc, wrap it tightly in plastic wrap, and refrigerate for at least 20 minutes.

While the dough chills, heat the vegetable oil in a large skillet over medium heat. Add the chopped onion, minced garlic, and Scotch bonnet pepper, sautéing until softened and fragrant, about 3 to 4 minutes.

Add the lean ground beef to the skillet, breaking it apart with a wooden spoon. Stir in the fresh thyme, curry powder, and ground allspice, cooking until the beef is fully browned and no pink remains.

Pour in the beef broth and stir in the breadcrumbs to bind the mixture. Reduce the heat to low and let it simmer for 3 to 5 minutes until the liquid is fully absorbed and the filling is thick, then set aside to cool.

Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper. On a lightly floured surface, roll out the chilled dough to about 1/8-inch thickness and cut out 8 circles using a 6-inch bowl or cutter.

Spoon about 2 to 3 tablespoons of the cooled beef filling onto one half of each dough circle. Fold the other half of the dough over the filling to create a half-moon shape, then press the edges together and crimp firmly with a fork to seal.

Place the sealed patties onto the prepared baking sheet and brush the tops lightly with the beaten egg wash. Bake for 20 to 25 minutes until the crust is beautifully golden brown and flaky. Let them cool for 5 minutes on a wire rack before serving warm with your favorite dipping sauce.