Ingredients for pie crust: 2 1/2 cups all-purpose flour 6 tablespoons sugar 1 teaspoon salt 260 g cold unsalted butter, cut into small cubes 1/2 cup ice water Ingredients for filling: 2 1/2 cups blueberries 1/2 cup sugar juice and zest from 1/2 lemon 1 tablespoon melted butter 1 tablespoon cornstarch egg for brushing sugar for sprinkling Preparation: Mix the flour, sugar, and salt together. Add the butter and start working the butter into the flour with your hands until there are pieces the size of large peas. Add the water and continue mixing just until the dough comes together. You don’t want the dough too wet, and you don’t want to mix in the water too much. Do not overwork the dough. Divide the dough in two, cover each half with plastic wrap, and refrigerate for a couple hours at least (overnight is best). You can prepare the dough the day or two ahead Toss the blueberries, sugar, lemon juice and zest, butter, and cornstarch in a medium bowl. Set aside. Preheat your oven to 200 oC. Line the bottom of a cookie sheet with parchment paper. Remove one of the covered dough halves from the refrigerator. Divide this in half and roll out on a floured board. Using a 7 cm round cutter, cut eight circles out of the pie dough. Place these on the parchment paper, evenly spaced. Spoon a small amount (1 tsp and a little sauce) into the center or each pie circle. Cut eight more circles out of the pie dough. Place each circle on top of the blueberry-topped bottom circles and press down the edges with fork. Brush with egg yolk and sprinkle with sugar. Cut some small slits in the top. Bake for 15-20 minutes, or until the filling is bubbly and pastry nice and brown. Cool on a wire rack. Repeat in three more batches with the rest of the pie crust and filling.