Chop the onion and boiled eggs into coarse pieces.

Heat olive oil in a pan over medium heat, add onion, and sauté until softened. Add ground beef and cook until browned.

Add chili powder, cumin, ketchup, garlic, salt, and pepper to the pan. Mix well and transfer to a tray to cool. Mix in the boiled eggs to complete the filling.

In a bowl, mix bread flour, cake flour, and salt. Add beaten egg, water, and vegetable oil, and combine until dough forms.

Knead the dough on a floured surface until smooth. Cover with plastic wrap and let rest for 20 minutes.

Divide the dough into 8 equal portions and roll each into a ball. Cover with plastic wrap and let rest for 10 minutes.

Roll each ball into a 10cm diameter circle using a rolling pin.

Place 1/8 of the filling in the center of each circle, fold in half, and seal the edges by pinching and twisting.