Preheat
oven to 425 degrees F. Roll out half the pastry and
line a 9 inch pie plate. Trim leaving 1/2 inch over
the pie plate.
Combine
rhubarb strawberries, sugar, cornstarch, lemon juice
and cinnamon. Place in the pie shell.
Roll
out remaining pastry and cut into 1 inch strips. Make
a lattice top crust on the pie by crisscrossing the
strips over the filling. Trim the strips even with the
pie plate. Fold the 1/2 inch of the bottom crust over
the ends of the strips. Seal and flute the edges. Brush
lattice with egg.
Place
on a baking sheet or tinfoil in the oven and bake for
15 minutes, until the crust starts to brown. Reduce
heat to 375 degrees and continue to bake for 50 to 60
minutes, until crust is golden, rhubarb is tender, and
filling is thickened.
