Remove one of the rounds of pastry from the refrigerator ten minutes before rolling it out and lining a 10" pie pan. Return to the fridge while preparing the filling.

Filling: Peel, core, and cut the pears into eighth-inch slices. Pit the cherries nad halve them, add them to the pears and set aside.

In a small bowl, stir together the sugars, spices, and Cleargel. Add this to the fruit, stir until just combined, then add the lemon juice and vanilla. Mix until the fruit is uniformly coated.

Assembly: Remove the pie pan from the fridge. Separate the egg and brush the egg white on pie crust. Spoon in the filling, mounding it up in the center. Dot the top with the butter, and return it to the fridge.

Roll out the top crust and cut it into strips that are a half- to one-inch wide. Weave into a lattice to top the pie. Refrigerate the pie for one hour or freeze it for a half-hour.

Baking: Place a rack in the bottom third of the oven and preheat it to 425°F.

Beat the egg yolk with the heavy cream. Remove the pie from the fridge and brush it with the egg wash, then sprinkle the sugar over all.

Bake the pie on a baking sheet for 15 minutes, or until the crust begins to turn golden. Reduce the oven temperature to 350°F, cover the edges with a pie shield, and bake 40 to 45 minutes more, or until juices are bubbling. Remove the pie from the oven and let cool for an least one hour before serving.