From Gourmet Magazine and slightly changed from this recipe
For tart dough
1 1/2 cups all-purpose flour
1 stick and 1 Tbs cold unsalted butter, cut into 1/2-inch pieces
1/4 cup sugar
1/2 teaspoon salt
1/2 teaspoon finely grated fresh lemon zest – (I didn’t have any)
2 large egg yolks
For filling
1/2 cup sugar
1 1/2 tablespoons cornstarch
Enough plums to fill up your pan
12 tablespoon fresh lemon juice
(makes one tart)
Preheat oven to 425F
Preparation
Make dough: Combine flour, butter, sugar, salt, and zest in a food processor and pulse until most of mixture resembles coarse meal with remainder in small (roughly pea-size) lumps. Add yolks and process just until incorporated and mixture begins to clump.
Ball up your dough, and when everything seems to be adhering to the ball, smash into your tart pan (or in my case Pyrex pie mold) and with the ball of your hand smooth it out to the edes, covering all crimps of the pan. Some recipes tell you to put this in the refrigerator, or in the oven for X amount of time. I did neither.
Stir together sugar and cornstarch in a large bowl. Add plums (cut, de-stone and cut into 1/8 sized pieces) and lemon juice and toss to coat. Let stand, stirring occasionally, 30 minutes, or until juicy. Arrange your plum pieces into a pretty rosette pattern until the tart crust is completely covered. Put excess plum juices over the plums.
Bake tarts in middle of oven 15 minutes, then reduce temperature to 375°F. Cover tarts loosely with foil and bake until plums are tender and juices are bubbling and slightly thickened, 40 to 50 minutes more. (Juices will continue to thicken as tarts cool.) Cool tarts completely in pans on a rack.
