1. In a medium bowl gently toss blueberries, rhubarb and 1/4 cup of sugar together. In a separate mixing bowl beat cream cheese until fluffy, beat in 1/4 cup sugar and lemon zest.
2. Preheat oven to 400 degrees F. Line a large baking sheet with parchment and grease well. Divide pie crust into 3 equal pieces and roll out on a lightly floured board into 1/8 inch thick circles. Trim the uneven edges if desired to make a uniform circle (save the scraps to decorate the top).
3. Place the crusts on the well greased baking sheet and spread 1/3 of the cream cheese mixture over bottom leaving a 1-2 inch border around the edge. Pile on 1/3 of the blueberry mixture and fold the dough up and over the side, starting in one place and pleating it around the blueberries. Brush with egg and sprinkle with sugar (raw sugar, if you have it). Repeat with the remaining two crusts. Stick all the scraps together, roll out and cut into small shapes to decorate the tops.
4. Bake about 20-25 minutes until crust is golden. If the juices overflow and cause the galettes to stick to the parchment, refrigerate and the parchment will easily peel off. Serve warm or chilled with fresh whipped cream.
Serves 3 or 6 — if you cut them in half
1. In a bowl, whisk together the flour, salt and 1/2 tablespoon of sugar. Using a pastry blender or 2 knives, cut in the butter until pea-size crumbs form. Add the water 1 tablespoon at a time and mix with your hands, adding more water as needed until the dough comes together. It should be moist but not sticky.
Turn the dough out onto a lightly floured surface and shape into a disk. Cover with plastic wrap and refrigerate for at least 1 hour.