Tart shell dough
Prepare and bake your tart dough. If you are going to bake our Tart dough, you can click on the ingredients list and follow the instructions. You can make 2 small tars (ring 12cm / 4.5 inch) or 1 tart (ring 24 cm / 9 - inch). When the tart dough is baked, cool it on the wire rack.
Bring double cream to a boil. Add chocolate to a large bowl. Remove the double cream as soon as the mixture boils up and pour it over the chocolate. Using a hand-held immersion blender mix the mixture for about 2 minutes or until shiny and blended. Add the sea salt and stir well. Gradually start adding cubes of cold butter. Mix it all well, using a hand-held immersion blender. This is your chocolate ganache. Pour it in the prebaked tart shells, while still hot/warm. Place in the refrigerator for about 2 hours to set.
Silky cacao glaze
Soak sheets of gelatin in a bowl, filled with ice cold water for about 10 minutes. Add water, caster sugar and unsweetened cacao powder to a saucepan and place it over low heat, stirring constantly. When the mixture slowly comes to a boil, add the double cream and remove from the heat. Lift sheets of gelatin from the water and squeeze them well to remove any water. Add to the mixture and combine all very well. Strain through a fine-mash strainer and set aside until needed.
chocolate ganache and glaze
Heat the cacao glaze to 40°C / 105 °F and pour it all over the set chocolate ganache, but be careful not to go over the tart shells.
Dust the chocolate tart with unsweetened cacao powder and sprinkle with chopped pistachios. Serve the chocolate tart at room temperature.