For the tart crust: Mix the flour, sugar, cardamom and salt in a food processor. Add the butter and shortening, and pulse until the mixture looks like coarse meal. Drizzle in the ice water and vanilla, and pulse until the dough comes together. Turn the dough out onto a piece of plastic wrap and form into a ball. Wrap and refrigerate until firm, about 1 hour.
For the blueberry compote: While the dough is resting, place the blueberries, sugar and lemon juice in a pot and bring to a boil. Boil for 8 to 10 minutes. Remove from the heat and add the cornstarch and water, stirring to combine. Return to the heat and simmer until the compote reaches a thick, jam-like consistency, about 8 minutes.
To assemble: Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper.
Roll out the dough to about 1/8-inch thick on a floured work surface and then cut into 4-by-3-inch rectangles using a pastry press or knife. Transfer to the prepared baking sheet. Place a heaping teaspoon of blueberry compote in the center of half of the rectangles and brush the edges with beaten egg. Top with the remaining rectangles and seal using a fork or dough crimper.
Bake the tarts for 10 minutes. Remove from the oven and brush the tops with milk. Return to the oven for another 10 minutes, until golden brown.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Wilma & Frieda, Palm Springs, CA