This is lightly adapted from Ina Garten but we used less cornstarch and more fruit. Notice that you'll have enough pastry for two crostatas from this recipe, but only enough filling for one. The extra pastry can be refrigerated or frozen for another time. Of course, you can always double the recipe for the filling below and then you'll have enough for both pastry crusts.
Ingredients
For the pastry (makes 2)
2 cups all-purpose flour
½ cup sugar
½ teaspoon kosher salt
2 sticks (1/2 pound) very cold unsalted butter, ½-inch diced
½ cup ice water
For the filling (makes 1)
⅛ cup cornstarch (Ina uses ¼ cup), or omit it altogether, but if you do, you will get a soupier result
2 pounds fresh rhubarb, sliced ½-inch thick, about 4 cups
8 ounces fresh raspberries
⅔ cup white sugar
1 teaspoon gated orange zest
½ cup freshly squeezed orange juice
1 egg beaten with 1 tablespoon water for egg wash
1 teaspoon turbinado sugar (Sugar in the Raw)
Instructions
For the pastry, place the flour, sugar, salt in a food processor fitted with the steel blade and pulse a few times to combine.
Add the butter and and pulse about 15 times or until the butter is the size of peas. With the motor running, add the ice water all at once through the feed tube and keep hitting the pulse button until the dough just comes together.
Turn onto a well-floured board, cut in half, and form into two disks. Wrap and refrigerate for at least an hour (At this point you can wrap the second dough well and freeze for another time).
For the filling, if you're using cornstarch, place 3 tablespoons of water in a small bowl, whisk in cornstarch and set aside.
In a large Dutch oven or saucepan, combine the rhubarb, raspberries, sugar, orange zest, and orange juice.
cook over medium heat for about 5 minutes, until some of the juices are released.
Stir in the cornstarch, if using, and bring to a boil, lower the heat, and simmer for 2 minutes.
Refrigerate for 30 minutes until cool.
Preheat the oven to 425 degrees. Line a sheet pan with parchment paper.
Roll the pastry into an 11 or 12-inch circle on a lightly floured surface and transfer to the prepared sheet pan. Pile the raspberry rhubarb mixture onto the pastry, leaving a 1½-inch border all around.
Fold the border up over the filling and press lightly.
Brush the pastry with the egg wash, sprinkle just the pastry with the turbinado sugar, and bake for about 30 minutes, until the pastry is browned.
Cool for 30 minutes and serve warm or at room temperature.
Recipe by Food and Friendship at https://www.foodandfriendshipsantabarbara.com/2017/09/04/cobbler-crisp-crumble-crostata-oh-my/