Adapted from Fine Cooking. A dessert that can be personalized by the combination of fruits available or desired. The free form shape of the tart means that you don't have to search for special baking equipment.
In a stand mixer, combine dry ingredients for crust and stir to mix. On low speed, add butter until the flour is crumbly and the butter is the size of peas.
Mix egg yolk and milk together then add to flour mixture until just combined (about 15 seconds).
Remove the mixture from the bowl and put on a floured surface. Knead quickly until it just comes together. The dough will be dotted with butter spots throughout. Tightly wrap in plastic wrap, refrigerate and let it rest for 15-20 minutes.
Preheat oven to 350 degrees.
In the meantime, in a large bowl toss together ingredients for the fruit filling; set aside.
Remove pastry ball from refrigerator and place on a floured surface or a floured Silpat. (Just rolling between 2 pieces of plastic wrap may be easier.) Place the plastic wrap on top of the dough ball and proceed to roll out until approximately 12 inches across and 1/8 inch thick. Transfer crust to a baking sheet.
Ladle filling in the center, leaving a few inches of dough around the edges and pull over the free edges on top of the fruit filling leaving the center exposed. Brush the dough edges with egg wash and top with sugar in the raw or brown sugar.
Cook for 55 minutes or until crust is browned and the fruit is bubbling.