If you've never had pie made from wild blueberries before, you'll be bowled over by the intensity of this one. The light, tender crust provides a sublime foil for the deeply flavorful fruit. Take heart if you can't find fresh wild blueberries in your area—frozen ones also yield excellent results.
04Roll out remaining dough on a lightly floured surface with lightly floured rolling pin into an 11-inch round. Cut out 5 or 6 small holes with small decorative cookie cutters or use a small knife to slash steam vents toward center.
05Spoon filling with any accumulated juices into shell, dot with butter, and cover with top crust. Trim top crust with kitchen shears, leaving a 1/2-inch overhang. Fold overhang of top crust under bottom pastry and press against rim of pie plate to reinforce edge, then crimp decoratively and brush with egg wash.
06Bake pie on hot baking sheet in oven 30 minutes, then cover edge with a pie shield or foil to prevent overbrowning. Reduce oven temperature to 375°F and continue to bake until crust is golden and filling is bubbling, 45 to 50 minutes more.
07Cool pie completely on a rack, about 4 hours (filling will be runny if pie is still warm).