To prepare the crust, put the whole-wheat pastry flour, plain flour, granulated sugar and salt in the bowl of a food processor and pulse 3 times to combine. Add the butter and pulse about 12 times, until you get a pebbly, coarse texture. In a small bowl combine the buttermilk and ice water. Add the buttermilk-water mixture and pulse 3 to 5 times more to combine. Pat the dough into a 4-inch round and wrap in plastic wrap. Place in the freezer for 10 minutes, or make ahead and refrigerate for up to 1 day.
In the meantime, preheat the oven to 220°C, and prepare the filling. Core the apples and cut them into 1/4-inch slices. In a large bowl toss the apple slices with the lemon juice. Add the dried cherries then sprinkle in the cornstarch, brown sugar and cinnamon and toss until the apples are evenly coated. Set aside.
On a lightly floured surface, roll the chilled dough into a large circle about 9 inches in diameter. Line a baking sheet with parchment paper, and draping the dough over the rolling pin, transfer it to the prepared baking sheet. If the dough breaks, patch it up with your fingers.
Arrange the apple mixture in a mound in the center on the dough, leaving a 1 to 2-inch border. Fold the border over the filling. It will only cover the filling partially and does not need to be even.
Bake the pie at for 15 minutes, and then reduce the oven temperature to 175°C, keeping the pie in the oven all the while, and bake for another 40 minutes, until the apples are tender and the crust is golden brown.
In a small bowl stir together the honey and boiling water to make a glaze. When the pie is done remove it from the oven and brush the honey glaze all over the top of the fruit and crust. Transfer to a plate to cool slightly. Cut into 6 wedges and serve warm or at room temperature.