Blueberries and nectarines are one of the best flavor combinations to ever happen to summer fruit pies. Wrap them in a cornmeal crust, and you've got a showstopper of a pie that is perfect for the 4th of July, and all summer long.
8ounces(2 sticks) cold unsalted buttercut into ½-inch pieces
1pound(455 g) fresh nectarines (about 4)cored and sliced
4cups(560 g) fresh blueberries
Zest of 1 lemon
¾cup(150 g) sugar
¼cup(30 g) cornstarch or tapioca starch
Egg wash or milkfor glaze
Raw sugarfor garnish
Make the crust: Stir the flour, cornmeal, salt, and sugar together in a large bowl.
Add the butter pieces and coat with the flour mixture using a spatula. With a pastry blender, cut the butter into the flour mixture, working quickly until mostly pea-size pieces of butter remain (a few larger pieces are okay; be careful not to overblend).
Combine the water, cider vinegar, and ice in a large measuring cup or small bowl. Sprinkle 2 tablespoons of the ice water mixture over the flour mixture, and mix and cut it in with a bench scraper or spatula until it is fully incorporated.
Add more of the ice water mixture, 1 to 2 tablespoons at a time, and mix until the dough comes together in a ball, with some dry bits remaining.
Squeeze and pinch with your fingertips to bring all the dough together, sprinkling dry bits with more small drops of the ice water mixture, if necessary, to combine.
Shape the dough into a flat disc, wrap in plastic, and refrigerate for at least 1 hour, preferably overnight, to give the crust time to mellow.
Wrapped tightly, the dough can be refrigerated for 3 days or frozen for 1 month.
Preheat the oven to 425°F. Roll out half of the dough into a circle about 11 inches in diameter. Transfer it to a 9-inch pie plate. Trim the overhang to 1 inch and refrigerate the crust.
Make the filling: In a large bowl, toss together the nectarines, berries, lemon zest, and vanilla. In a separate bowl, mix together the sugar, cornstarch, cinnamon, and salt. Just before adding the filling to the pie plate, toss the fruit in the dry ingredients. Brush the rim of the bottom crust with egg wash or milk.
Roll out the second half of the dough into a circle about 11 inches in diameter. Lay it over the filled pie. Trim the edges, and tuck the top crust over the rim of the bottom crust to form a tight seal. Crimp the edge into whatever pattern you like. Brush the top crust with egg wash or milk, sprinkle it with raw sugar, and cut a few slits to allow steam to escape.
Put the pie on a baking sheet and bake it for 20 minutes, turning it once halfway through. Lower the temperature to 350°F and bake it for 30 to 40 minutes more, until the crust is golden and fully baked and the juices have thickened (mine required an additional 85 minutes, believe it or not, but my blueberries started out frozen and needed more time to catch up–the key is to watch for the visual cues to know it’s done ie bubbly juices. If the edges of your crust brown too quickly, use a pie shield or tent the edges with foil).
Remove the pie to a rack to cool completely, at least 1 hour. This pie can be refrigerated for up to 1 week, covered in plastic wrap. Let it come to room temperature before serving, or warm it in a low oven. It can be kept frozen for up to 2 months: Wrap it in plastic, then in foil, and let it come to room temperature before serving.