Preheat the oven to 180°C (350°F) and line a large baking sheet with parchment paper.
Heat 2 tablespoons of olive oil in a large skillet over medium heat and sauté onions until soft and translucent.
Add the ground beef to the skillet and cook until browned, using a wooden spoon to break it into small crumbles.
Stir in the salt, black pepper, cumin, Aleppo pepper, and pine nuts, then cook for 3 minutes before removing from heat to cool.
In a separate bowl, whisk together the yogurt, milk, 0.25 cup olive oil, and the egg to create a liquid glaze.
Lay a sheet of yufka or phyllo on a flat surface and brush it lightly with the yogurt glaze.
Spread a thin line of the beef mixture along the edge of the pastry.
Roll the pastry into a long cylinder, then coil the cylinder around itself to form a spiral shape.
Place the spiral on the prepared baking sheet and repeat with the remaining ingredients.
Brush the tops of all spirals with the remaining glaze and sprinkle with nigella seeds.
Bake for 35 to 40 minutes until the boreks are golden brown and crisp.