Prepare your pie crust according to your chosen recipe or package instructions. If you’re using homemade, chill it in the refrigerator for about one hour. This helps the gluten relax, making it easier to roll out later.
While the crust chills, preheat your oven to 425°F. This high initial temperature helps create a crispy, flaky crust.
Divide your dough into two halves, making one slightly larger than the other. Store the smaller half in the refrigerator while you work with the larger piece.
On a floured surface, roll out the larger half into a 12-inch circle. If the dough feels stiff, let it sit at room temperature for a few minutes. When rolling, start from the center and work outward, turning the dough occasionally to maintain an even thickness.
Transfer the rolled-out dough into a 9-inch pie plate. Avoid stretching it; simply ease it into the plate. Trim any excess dough hanging over the edges, leaving about a half-inch for crimping later.
Place the bottom crust in the freezer while you prepare the filling. This will help keep it from getting soggy once the filling is added.
In a mixing bowl, combine sliced rhubarb, ¾ cup granulated sugar, flour, salt, and the optional nutmeg. Mix well until the rhubarb is fully coated.
Remove the chilled bottom crust from the freezer. Sprinkle the remaining 1 teaspoon of granulated sugar evenly over the bottom. Pour the rhubarb mixture into the crust, spreading it out evenly. Dot the top with butter.
Roll out the second portion of dough into an 11-inch circle. If you want to create a lattice top, cut it into strips and arrange them over the filling in a crisscross pattern.
Trim the top crust to a half-inch overhang, then tuck it under the bottom crust and crimp the edges using your fingers or a fork. This seals the pie.
Cut several vents in the top crust to allow steam to escape during baking.
Brush the crust with the egg wash for a beautiful golden finish. Place the pie on a parchment-lined baking sheet to catch any drips.
Bake in the preheated oven for 15 minutes, then reduce the temperature to 375°F and continue baking for 50 to 55 minutes, or until the crust is deep golden and you see filling bubbling out of the vents.
Once baked, let the pie cool completely at room temperature for at least 4 hours. This step is crucial for the filling to set properly.
Slice your Rhubarb Pie and serve it plain or with a generous dollop of whipped cream. Enjoy!
