Put the milk, 195 g sugar and vanilla bean seeds and pod into a saucepan over medium-low heat. Gently heat the milk, stirring occasionally, and bring to the boil. As soon as it begins to boil, remove and discard the vanilla pod.
While the milk is simmering, pour in the semolina and whisk it continuously until thickened – about 5 minutes.
Whisk in the egg yolks one by one, then turn off and remove from the heat. Stir through the blueberry jam and fresh/frozen blueberries until combined. Set aside to cool as you prepare the pastry.
Preheat the oven to 180°C.
Grease a 20 x 30 cm deep ovenproof dish with some of the melted butter.
Separate the strands of the kataifi pastry with your fingers. Lay half of the kataifi evenly into the bottom of the greased dish, pressing down firmly. Drizzle half of the melted butter over the pastry.
Spread the cooled semolina mixture over the pastry evenly, then lay the remaining kataifi over the top. Drizzle over the remaining melted butter, put it into the oven, and bake for 1½ hours, or until golden.
Start to make the syrup about 10 minutes before the galaktoboureko comes out of the oven. Pour the hot syrup over the galaktoboureko as soon as it comes out of the oven.
Allow it to cool completely before cutting into portions. Refrigerate in a sealed container.
Simply put the sugar and water into a small saucepan over medium heat. When it comes to the boil, allow it to bubble for 10 minutes. Turn the heat off and pour the hot syrup over the galaktoboureko as soon as it comes out of the oven.