In a bowl mix the flours with the sugar, salt, egg and cold butter into small pieces. Work everything with your hands until you get a crumb mixture.
At this point add the cold milk or water (1 or 2 tablespoons based on the flour) and briefly knead the dough on a pastry board.
Flatten the dough, then wrap it in plastic wrap and place in the refrigerator to cool for 2 hours In the meantime, place the blueberries in a bowl and add the lemon juice, starch and sugar. Mix well.
Take the dough out of the refrigerator and spread it on a lightly floured surface in a circle with a thickness of 6mm.
Roll the dough around the rolling pin and roll it out on a baking tray lined with parchment paper.
Pour the blueberries in the center, leaving a border of about 5 cm.
Fold the edges inwards, slightly overlapping them.
Place the galette in the refrigerator for an additional 30 minutes.
Preheat the oven to 200 °. Brush the pasta with a little milk and sprinkle with brown sugar.
Bake at 200 degrees for 40/45 minutes or until the cake turns golden brown.
Remove from the oven and leave to cool on a wire rack.
Serve with a scoop of cream or vanilla ice cream.
