Blueberry Galette

Bahan-bahan (6 porsi)

• 1 1/2 cups all purpose flour ( or plain flour)
• 1/2 cup confectioners’ sugar
• 1/4 teaspoon salt
• 1 stick (4 oz. / 115 g cold unsalted butter)
• 1 large egg (beaten)
• 4 cups blueberries
• 1/2 cup granulated sugar
• 2 1/2 tablespoons cornstarch
• 1 lemon zest
• 2 tablespoons instant tapioca
• 1 egg (beaten)
• 1 tablespoon Demerara sugar (for sprinkling, (or use regular sugar))