2 cups all-purpose flour
3/4 cup finely chopped walnuts
3/4 cup light brown sugar
12 tablespoons cold unsalted butter diced
1 egg yolk
2 pounds firm, ripe pluots, pitted and quartered lengthwise
Preheat the oven to 400f Combine the flour, walnuts, and sugar in a large bowl. Add the butter and the egg yolk. Mix, either by hand or with an electric mixer, until crumbly. Press 1 1/2 cups of the crumb mixture in an even layer into the bottom of a 9 1/2-inch springform or tart pan. Arrange the pluots in the pan, skin side down, to form a flower pattern; begin at the outside and work your way in. Sprinkle the rest of the crumb mixture evenly over the pluots. Bake the tart for 40 to 50 minutes, or until it's lightly browned and the pluots juices are bubbling. Remove from the oven and cool for 10 minutes. Remove from the pan and transfer the tart to a flat plate. Serve warm or at room temperature.