In a pan, heat the olive oil and sauté the chopped onion for 3-4 minutes. Add the minced meat and sauté for about 10 minutes until well-browned and cooked through. Pour in the white wine and let it boil until the alcohol evaporates. Stir in the tomato paste and cook briefly, ensuring it is well combined and fragrant.
Add the hot water and let the mixture simmer on medium heat until the meat is fully cooked. Stir in the cinnamon, dried mint, salt, black pepper, and parsley. Add the flour, mixing well to incorporate it into the minced meat.
In a small bowl, beat the egg and combine it with the cornflour to prevent curdling when added to the meat. Pour the egg mixture into the minced meat, followed by the warm milk and grated halloumi. Stir everything well and let the mixture cook for 1-2 minutes. Turn off the heat and allow the filling to cool and set.
Preheat the oven to 180°C. Lay one sheet of puff pastry on the bottom of a 24x34 cm pan and pierce it with a fork. Spread the cooled minced meat mixture evenly on top. Cover with the second sheet of puff pastry, trimming any excess. Brush the top with the beaten egg and sprinkle with sesame and black sesame seeds.
Score the pie into 12 or more pieces before baking. Place in the preheated oven and bake for 1 hour, until golden brown and fully cooked.
Allow to cool slightly before serving. Enjoy your delicious mince pie!