To make dough, stir flour with salt in a large bowl. Cut in butter with a pastry blender or your fingertips until mixture resemble coarse meal. Whisk egg yolk with 1/4 cup (60 mL) ice water and stir into the flour mixture until dough comes together.
Form dough into a ball and flatten into a large disk. Wrap in plastic wrap and refrigerate for at least 1 hour before rolling.
Meanwhile, heat oil in a large skillet set over medium-high heat and cook beef with salt for 6 to 8 minutes or until lightly browned. Add onions, peppers and chili powder and cook, stirring for 3 to 5 minutes or until vegetables are soft and tender.
Add tomato paste; cook for 1 minute. Add 1/3 cup (75 mL) water, capers and raisins and cook for 3 to 5 minutes or until pan is dry. Stir in parsley and cool completely.
Assembly: Preheat oven to 400°F (200°C). Whisk remaining egg yolk with 1 tbsp (15 mL) water to make egg wash; set aside.
Meanwhile, roll out dough on a lightly floured surface until 1/8-inch (3 mm) thick. Using a 4-inch (10 cm) round cutter, cut dough to make 8 rounds. Reroll scraps to make 8 more rounds.
Brush edges of each round with egg wash. Add 2 tbsp (30 mL) beef filling to the centre of each round. Fold to enclose the filling and seal edges with a fork and brush with egg wash. Place on prepared-paper lined baking sheet and bake for 20 minutes or until pastry is golden brown. Cool for 10 minutes.
Serve with light sour cream for dipping, if desired.