Ingredients: Gather 4 cups of chopped rhubarb, 1 ⅓ cups of sugar, 6 tablespoons of all-purpose flour, 1 tablespoon of butter, and a double crust for a 9-inch pie.
Preheat Oven: Preheat your oven to 425°F (220°C).
Prepare Rhubarb: Wash and chop the rhubarb into ½-inch pieces.
Mix Filling: In a bowl, combine rhubarb, sugar, and flour, mixing well.
Fill Crust: Line a 9-inch pie pan with one of the crusts and pour in the rhubarb mixture.
Add Butter: Dot the filling with small pieces of butter.
Top Crust: Cover with the second pie crust, seal the edges, and cut small slits in the top to vent.
Bake Pie: Bake in the preheated oven for 45-50 minutes, until the crust is golden brown and the filling is bubbling. Cool before serving.