In a large bowl whisk together 1/2 cup flour, cinnamon and nutmeg. Gently stir in blueberries and chopped rhubarb pieces with spatula until well coated. Pour in honey and stir softly until incorporated.
Divide pie crust in half and roll one half onto lightly floured surface to about 1/8 inch thick 12 inch wide circle. The circle should be a couple inches larger than your pie pan.
Carefully place crust into pan and use fingers tips to softly press into the corners, allowing excess crust to lay over the sides of the pan.
Spoon blueberry mixture into prepared pie crust.
Roll out second half of pie crust.
Use your cookie cutter to create shapes with the remaining dough pieces. Place across your uncovered filling in any pattern.
Brush egg wash onto dough cutouts and sprinkle with sugar. Place pie pan on cookie sheet and put in the oven.
Bake for 20 minutes.
Remove from oven and lightly cover pie with aluminum foil (tent slightly) to prevent burning the crust. Continue to bake for 30-40 minutes.
Pie is ready when filling is bubbly and crust is golden brown.
Place pie on cooling rack and allow to cool for 15-20 minutes before serving.