Blueberry Tart in Lemon Shortbread Pastry

Directions

1. Heat oven to 350 degrees F. Cut a large piece of heavy duty aluminum foil and place it shiny side down on a large cookie sheet. Butter the foil.
2. In a large electric mixer fitted with the paddle, blend the butter, sugar and lemon zest until thoroughly mixed. Add flour, 1 cup at a time, until well incorporated. Add the lemon oil before you add the last cup of flour. Place the mixture on the prepared cookie sheet and shape the dough into the shape of a kidney bean about 12 inches long. The bottom should be 1/2-inch thick. Make sure the sides are at least 1 inch higher than the bottom. Prick all over the bottom with a fork and bake for 10 minutes. Remove the shell from the oven and push the dough down around the edges. Return to the preheated oven and continue baking for 20 more minutes or until the shortbread is golden and tinged with brown edges. Remove from the oven and allow to cool thoroughly.
3. Blend 2 tablespoons of Crème de Cassis with the water in a 1-cup measure. Sprinkle the gelatin over, and make sure that all the gelatin absorbs as much liquid as possible
4. In a saucepan, combine lemon juice, sugar, cardamom, sea salt and 3 cups of blueberries. Bring to a simmer and cook, stirring occasionally, for 10 minutes. Remove pan from the heat and stir in the gelatin mixture and vanilla.
5. Transfer the blueberry mixture to a stainless steel bowl set in a bowl of ice water, and stir until very thick but NOT set -- about 15 minutes. Fold in the remaining berries. Pour filling into the crust and distribute evenly over the whole. Cover loosely with waxed paper, and refrigerate for at least 4 hours, or until set.
6. Serve the tart with clouds of freshly whipped cream.