Filling:

1. Heat 2 tbsp olive oil in a saucepan over medium heat.
2. Add 2 chopped onions, 2 minced garlic cloves, and 3 chopped celery sticks.
3. Sauté until soft and fragrant.
4. Add 5 sliced button mushrooms, cook another 2 minutes until soft.
5. Add 400 g beef mince and 400 g pork mince, breaking them up with a spoon. Cook until the meat is browned.
6. Stir in 3 tbsp tomato purée, 1 grated large tomato, 2 tbsp Worcestershire or soy sauce, salt, black pepper, 1 tsp paprika, 1 tsp dried thyme, 1 tsp dried marjoram, and 1 1/2 tsp dried parsley.
7. Pour in 1 1/2 cups of beef stock, then bring to a simmer for 10 minutes to concentrate the flavours.
8. Add 2 cubed large carrots and 2 cubed large potatoes, and simmer for another 15 minutes until the vegetables are tender and most of the liquid has evaporated.
9. The mixture should be thick and nearly dry to prevent soggy pastry.
10. Let filling cool completely before using.

Puff Pastry:

1. Sift 1 3/4 cups of cake flour and 1 ml of salt into a bowl.
2. Rub in 1 portion of 200 g cold butter until it looks like breadcrumbs.
3. Add 80 ml ice-cold water, cut in with a knife, and knead lightly to a firm dough.
4. Roll dough into a 26 x 32 cm rectangle on a floured surface.
5. Grate the 2nd portion of butter on top, fold like an envelope, and roll out again.
6. Grate the 3rd portion, fold to close. Wrap and chill for 1 hour.
7. Half the pastry, roll one half to 3 mm thick, and line a greased baking dish.
8. Add cooled mince filling. Roll the remaining pastry to 3 mm thick, place on top, make a slit for steam, and brush with 1 beaten egg.
9. Bake in a preheated oven at 220°C for 15–20 minutes, or until golden.