**Making the dough:
In a bowl, add flour, salt, sugar whisk well. Add butter and using a fork or your fingertips combine with flour until the mixture looks like coarse crumbs. Add water and gather to form a dough, do not knead. (If you have a food processor, then add all ingredients together and pulse.)
Shape dough into a disk, cover with plastic wrap and refrigerate for 45 minutes to an hour. (You can make this dough at night and use it next day if you wish.)
**Making the filling:
Mix flour with water and keep aside.
In a pan, add the oil and onion, sauté until onion is caramelized.
Add the black pepper, oregano, and sausage. Pour the flour water mixture and stir on medium heat.
Pour the milk, season with salt, and keep stirring on medium heat until you get a thick creamy consistency.
Let the filling come to room temperature.
**Making the Galette:
Preheat oven to 190C/375F.
Since the dough is very delicate, cut enough parchment paper to cover your baking tray. Place parchment paper on your working surface and dust with flour.
Place the dough on the parchment paper and roll out to 12-13 inches wide. If the dough is hard, then keep it out of the fridge 3 minutes before rolling.
Place the parchment paper with the dough in your baking tray.
Pile the filling in the center of the dough, then spread evenly but keep it 2.5 inches away from the edges.
Fold doughs edges, up and to the center do this clockwise.
Brush the edges with milk.
Bake the Galette for 30 to 40 minutes, or until the crust is golden brown.