Divide the pie dough into two equal pieces. Roll out the bottom crust and put into a 10-inch pie dish. Refrigerate until needed.
Roll out the top crust and using a pastry wheel, cut the dough into 1/2-inch wide strips. Lay these strips on a baking sheet and refrigerate.
Combine the water and sugar in a sauce pan large enough to later add the rhubarb and, over low heat, begin to cook the syrup. Bring to a slow simmer and cook for 2 to 3 minutes before adding the rhubarb pieces. Cook the syrup rhubarb for 5 minutes, remove from the heat and allow to steep for 20 minutes. Strain out the rhubarb and set aside.
Mix the almond liqueur with the cornstarch well (add a few drops of water if necessary to remove all lumps) and stir into the cooled syrup which is now a wonderful rhubarb color. Place this back on the stove and cook the syrup until thick about 5 to 6 minutes.
Return the rhubarb to the and syrup, add the strawberries and stir to combine. Remove from the heat and cool completely for 1 hour.
Pour the fruit filling into the pie dish lined with the bottom crust. Lay half the strips across the top of the pie, leaving 1/2-inch of space between each strip. Brush the strips with the egg wash water mix and lay the remaining strips of dough at a 45 degree angle over the first strips to create a lattice top. Brush these strips with the remaining egg wash.
Place the pie dish on a cookie sheet and put the cookie sheet and pie dish setup into the oven on a shelf set in the middle of the oven. Bake for 45 minutes, turning the whole setup once so that the pie bakes evenly.
Remove from the oven and allow to cool for at least 30 minutes.