Roll half the pie dough out to about 3 inches wider than the pie pan, and transfer it to the pie dish. Refrigerate the bottom crust while preparing the filling.
Place the chopped rhubarb, halved strawberries, sugar, cornstarch, and salt in a large bowl and toss together to coat the fruit in the dry ingredients.
Transfer the filling to the refrigerated pie crust.
Dot with butter, and refrigerate while the top crust is prepared.
Roll the second half of the pie dough out to about 3 inches wider than the pie pan.
Cut into strips and arrange in a lattice pattern over the filled pie.*
Trim excess, roll & crimp the edge, brush with egg wash, and sprinkle with clear sparkling sugar.
Bake for 20 minutes at 425 degrees F, then lower the oven temperature to 350 degrees F and bake for an additional 45 to 55 minutes, or until evenly browned and bubbling.