• Preheat Oven to 350°F

For the Filling.

• Pour oil into a saucepan over medium heat, add onion and sauté for 2 minutes. Then add beef and cook for about 5 minutes until some water dries off.
• Add the rest of the ingredients and cook for another 3 minutes. Make sure there isn't too much water in the filling, like pies will be soggy.
• When the filling is ready, remove it from heat and set aside.

For the dough

• Add flour, butter and salt in a large mixing bowl and rub everything with your hands until crumpy.
• Pour in water in batches, and egg, mix with your hands until everything combines.
• Transfer the dough to the flour-dusted work surface and knead until the dough is ready. Do not over-mix or work the dough; it will make it hard and non-flaky. Divide it into the number of pies you want, flatten each portion, and then cut it using a small bowl or meat pie cutter.
• Add the filling to the dough, fold to meet the edges, and seal using the fork. Arrange the pies on the baking pan lined with a baking mat or sheet, pierce a fork on top of each pie and apply egg wash (beaten egg yolk) using a brush.
• Place in the oven and bake for 30 minutes at 350 degrees F. When fish pies are ready, remove them from the oven and serve hot.