Put the flour, sugar, salt, and butter in a food processor. Pulse four times for 1 second each. The butter will still be quite chunky. Combine the cider vinegar with 3-1/2 tablespoons ice water in a liquid measuring cup. Slowly pour the water mixture through the feed tube while pulsing very rapidly--a fraction of a second for each pulse--until the dough looks like it will gather into a mass, about 30 quick pulses. Stop just short of the dough forming a ball. Turn the dough out onto a lightly floured surface and shape it into a 4-inch round or square (depending on the shape of your pan; see the filling directions below). Wrap tightly in plastic and refrigerate for 1 hour or up to a day.

Roll the dough on a lightly floured surface into a 10-1/2-inch round or a 9-1/2-inch square. Prick with a fork at 1-inch intervals and carefully set the dough on an ungreased baking sheet. Cover with plastic wrap and refrigerate for 30 minutes.

Position a rack in the middle of the oven and heat the oven to 400 degrees F. In a small bowl, mix the egg yolk and 1/2 teaspoon water with a fork. Brush all of it over the chilled pastry and sprinkle with the almonds. Bake the pastry until lightly golden brown, about 15 minutes (it won't be fully cooked). Set the baking sheet on a rack to cool. While the pastry bakes, assemble the filling.

Butter a round 10x2-inch ovenproof dish or 9-inch square baking pan.

While the pastry is baking, bring a small pot of water to boil. (If using nectarines, skip this step.) Using a slotted spoon, put one peach in the water. Wait 45 seconds and then immerse the peach in a medium bowl of ice water until cool enough to handle and slip off the skin. (If the skin doesn't come off easily, repeat the blanching and cooling steps.) Repeat with the remaining peaches.

Halve the peaches or nectarines and remove the pits (quarter the fruits if they cling to the pits). Cut the fruit into 1/2-inch-thick slices and set aside. Rinse the blueberries under cold tap water, drain, and pat dry on paper towels.

In a large bowl, whisk together the sugar, brown sugar, cornstarch, salt, and allspice. Add the peaches or nectarines, blueberries, ginger, lime zest, and lime juice. Fold together with a rubber spatula, making sure the ginger and lime zest are evenly distributed, and turn the mixture into the prepared pan. Cover loosely with foil.

Bake for 30 minutes at 400 degrees F. Reduce the heat to 350 degrees F and continue baking until the fruit is just tender and the juices are just beginning to bubble, about 15 minutes. Slip the pastry on top of the fruit and continue baking until the pastry and almonds are a rich golden brown and the juices appear thick and bubbly, another 20 to 25 minutes. Halfway through this time use the back of a large metla spatula to gentkly press the pastry into the fruit so that the two integrate better. Set the pandowdy on a cooling rack. Serve warm or at room temperature.