2 cups bleached all-purpose flour
2 sticksunsalted butter, chilled and cut into 1/2-inch cubes
1/2 teaspoon salt
6 to 8 tablespoons ice water
For the ganache:
2 oz. semisweet chocolate chips
¼ cup heavy cream
1 tbsp. unsalted butter, at room temperature
For the filling:
8 oz. cream cheese, softened
½ cup confectioners? sugar, sifted
½ tsp. vanilla extract
2 tbsp. milk
1/2 pint fresh organic blueberries
Melted semisweet chocolate, for drizzling
Place the flour, butter, and salt in a food processor fitted with a steel blade. Pulse about 24 times, then open the machine and lift a handful of crumbs. The largest pieces of butter should be the size of raw grains of rice or barley. If there are larger pieces, continue to pulse the mixture. When the butter pieces are the correct size, transfer the mixture to a large mixing bowl. Sprinkle 6 tablespoons of ice water onto the dough. Spread the fingers of one hand as if you were about to grab a large ball, and using your rigid fingertips as if they were a large fork, stir the dough quickly and briefly until the liquid is incorporated. Squeeze a handful of the dough in your palm. The dough should have just enough moisture to stay together. Break the piece in half. If it seems dry and crumbly, cautiously add more water a few teaspoons at a time until you can squeeze it into a ball that will not crumble when broken apart. If your kitchen is reasonably cool, the butter was cold, and you used ice water, the dough should be at just the right stage of malleability for rolling out, and it will be easiest to work with immediately. If your kitchen is very warm, wrap the dough in plastic wrap and refrigerate it for about 15 minutes.
Turn the pastry dough out on a lightly floured board and shape into a disk and dust the top lightly with flour. Begin to roll out the dough, using quick but gentle strokes with the pin. Start with the pin in the middle of the round and roll to the top, then to the bottom. Rotate the dough 1/4 turn each time you roll to be sure the dough is not sticking and use additional flour as necessary. When the round is larger than 12 inches and about 1/8 inch thick, roll dough onto rolling pin, then unroll onto tart pan. Push dough into tart shell firmly and then freeze for 30 minutes.
Preheat the oven to 375°F. Lay a large piece of foil over the dough and press firmly. Bake the tart shell for 15 minutes, then reduce the heat to 350°F and continue to bake until it is an even golden brown, 8 to 12 minutes longer. Lift a shell with a spatula and check that the underside is evenly brown. If the tart shells puff up during baking, press down the center of the pastry with the back of a large spoon. Remove foil from dough and bake another 5 minutes until golden. Remove from oven and allow to cool completely.
To make the ganache, place the chocolate in a heatproof bowl. Bring the cream to a simmer in a small saucepan. Remove from the heat and pour over the chocolate. Let sit 1-2 minutes to melt the chocolate. Whisk together until a smooth ganache forms. If there are still bits of unmelted chocolate, microwave in 10 second intervals, whisking in between, until the ganache is completely smooth. Whisk in the butter. Spread the ganache in a thin even layer over the bottom of the cooled tart shell. Allow the ganache to set before proceeding.
To make the filling, beat together the cream cheese and confectioners? sugar in a bowl on medium-high speed until smooth. Blend in the vanilla and milk or cream.
Spread the cream cheese mixture over the cooled ganache in the tart shell.Starting from the outside and working toward the center, place the sliced blueberries in concentric circles slightly overlapping each other. Gently press the berries into the cream cheese mixture to help keep them in place. Drizzle with melted chocolate, if desired. Chill until ready to serve.