For The Lemon Mousse:
In a non-reactive bowl* (see note below), whisk together the lemon zest, juice, egg yolks and sugar. Place over simmering water in a double boiler and cook, whisking constantly, until the mixture is firm and thickened, about 5 minutes. Remove and allow to cool, cover with plastic wrap and refrigerate at least 3 hours.
To Prepare the Tart Shells:
In a large bowl, mix together the flour, butter, salt and sugar with a pastry blender or process in a food processor. Add a few tablespoons of cold water just to bind the dough. Shape into a disc and cut the dough into quarters. Wrap in plastic wrap and refrigerate 2 hours.
Heat oven to 350ºF (180ºC).
On a lightly floured work surface, roll out each dough quarter and press into a 4-inch tart pan. Poke holes in the bottom with a fork. Bake for about 25 minutes or until golden brown. Remove from the oven and cool.
Meanwhile, whip the heavy cream until soft peaks form. Fold in the lemon mixture. Spread the mixture into the cooled tart shells and top with blueberries. If desired, garnish with mint sprigs and lemon zest.
Makes 4 (4-inch) individual tarts.
Non-reative Bowls or Cookware:
Non-reactive cookware is anything made of a material that does not react chemically to food cooked in it. Stainless steel is the most common material used to make non-reactive cookware.
Cookware made of aluminum, cast iron or copper can react with acidic foods such as tomatoes, lemons, vinegar, giving them a metallic taste; if cooked long enough, it will discolor the food as well. Other foods can be cooked in pans made of these materials without problems.
Most better quality aluminum and copper pots and pans are lined with stainless steel to make them nonreactive. You can also purchase aluminum cookware that has been anodized. This process changes the chemical makeup and makes the surface almost (but not completely) non-reactive. When in doubt, however, stick with stainless steel and avoid any adverse reaction entirely.
Date: November 11, 2002