Greg Patent makes the most of tart cherry season by preserving as much of the fruit as he can while setting aside cherries for this recipe. "Fresh sour pie cherries are as precious as rubies," Greg writes. "Bright and shiny like the gems they resemble, the sour Montmorency cherries have a short season (only 2 to 3 weeks in July) in western Montana, so I always pick some off a neighbor’s tree to use fresh and enough to freeze."