The crust is adapted from a Deborah Madison recipe. I use a food processor for the pastry, which is quick as a wink; you can also make it using a pastry cutter and good old elbow grease.

Steps

1. Make the crust: Combine the flours, sugar, and salt in the bowl of a food processor; pulse a few times to blend. Cut the butter into 10 chunks; add these to the dough and process until it forms pea-sized grains. Through the feed tube, pour in ⅓ cup ice water, and process until mixture begins to form a ball. (Add the rest of the water if necessary.) Gather the pastry neatly into a disk, wrap it in waxed paper, and refrigerate for 15 minutes.
2. Preheat the oven to 400 degrees.
3. Prepare the fruit: Slice the nectarines into bite-sized chunks and combine them in a large bowl with the other fruit. Toss with the sugar, tapioca, and lemon juice. Set aside.
4. Assemble the galette: Lightly flour your work space, then roll out the galette crust into a rough 14-inch circle. Carefully move the pastry to a baking sheet. Mound the fruit in the center of the crust, leaving a border of about 3 inches around the perimeter. Fold the edges of the crust inward and over the top of the fruit, overlapping it as you go, creating a rustic edge. When you are done, there should be a crustless circle in the center where the fruit shows through.
5. Finish the galette: Brush the crust with the melted butter and sprinkle it with the sugar. Bake the galette for 40 minutes, or until crust is golden. Cool for at least 30 minutes before serving, with ice cream if you wish.