It’s time, once again, to talk about elderberries. Back in season and growing with a vengeance on an old friend’s farm, they present me with the annual challenge of what to do with quarts and quarts of bold, earthy fruit. Last year I featured these tiny, bluish-black berries in a colorful sweet that I’d dubbed “Elderberries and Cream.” Consisting of stewed elderberries layered between white bands of homemade, vanilla-laced whipped cream, this uncomplicated dish was perfect for elderberry fans. Unfortunately, those preferring a milder last course were better off just skipping dessert for Elderberries and Cream was a heady, strong-flavored confection. This year I’ve opted for a treat that will satisfy a variety of tastes. Rather than only showcase elderberries, I’ve gone for all of summer’s fabulous foraged fruit—or at least all that I can pick at my friends’ farm—and made a dessert with the “fruits of the forest.” Years ago a family friend introduced me to fruits of the forest pie at the Tavern in New Wilmington, Pa. The memory of that deliciously complex …