1Combine the flour, cocoa, butter, Bonsalt and sugar in kitchen mixer or blender. Mix until crumbly. Add the egg, continuing to stir. Remove the dough and roll it into a ball. Wrap with plastic wrap and chill in the refrigerator for 30 minutes.
2Flour a working surface, place the dough on the surface and cover in plastic wrap, and roll out the dough.
3Line the heart-shaped tart tin with this dough and chill again in the refrigerator while preparing the filling.
4Put the cream in a saucepan and bring to a simmer.
5Break the chocolate into small pieces and heat in the microwave for 30 seconds. Remove, stir and repeat if the chocolate is still not completely melted. (30 seconds each time, otherwise the chocolate will start to burn)
6Once the cream starts to boil, add the chocolate, stirring well.
7Pour the mixture into the tart tin and bake in the oven preheated to 360°F for 15 minutes.
8Slice the pears. Remove the tin from the oven. Arrange the pear slices over the filling (which should be firm). Garnish with chopped nuts.
9Bake in the oven for 20 more minutes.
10Remove and let cool completely before removing the tart from the tin. Brush the pears with jelly.