01 -
Preheat the oven to 400 degrees Fahrenheit (200 degrees Celsius).
02 -
Mix the flour and sugar together in a large bowl. Add rhubarb and strawberries, toss with the sugar and flour mixture, and let stand for 30 minutes.
03 -
Pour the filling into the prepared pie crust. Dot the filling with butter, cover with the top crust, and seal edges using water.
04 -
Brush the top crust with the egg yolk, sprinkle with sugar, and cut slits in the top crust to allow steam to escape.
05 -
Bake the pie in the preheated oven until the filling is bubbly and the crust is golden brown, about 35 to 40 minutes. Let the pie cool on a wire rack before serving.