Roll the dough into a circle that's about 4-inches larger than the diameter of your pie pan. Gently place it in the pie pan without stretching it.
Trim the edge so there's a 1-inch overhang over the sides of the pie pan. Fold the excess dough under so it sits up on the rim of the pan and flute as desired.
Refrigerate the crust with you make the filling.
Beat the eggs with a handheld electric mixer until frothy. Add the sugar, butter, and flour and beat until smooth.
Whisk in the buttermilk, lemon juice, vanilla, and nutmeg. Pour into pie shell.
Bake until the center is firm, 40 to 60 minutes.
Cool the pie on a wire rack for about 1 hour before serving.
Notes
Make-ahead tips
Cover and store in the refrigerator for up to 5 days.
The pie dough can be prepared ahead of time and stored in the refrigerator for up to 5 days or in the freezer for up to 3 months.
You can freeze the pie after baking and completely cooling it. Cover with a double layer of plastic wrap before freezing. Freeze for up to 3 months. Thaw in the refrigerator or on the counter.