Mix the flour and salt together in a large bowl. Add the cold butter straight from the fridge into the flour and rub in the mixture. Add the sugar, mix together the eggs and egg yolk, and add to the mixture. Gently mix with a dough scraper or with your hands until the dough comes together in a ball. Lightly flour your work surface, tip the pastry ball onto it, and knead with your hands until you have a smooth dough. Wrap it in clingfilm and let it rest in your fridge for at least 1 hour. 

For the shortcrust pastry, preheat the oven to 190C°. I have a baking tin which doesn't need greasing, if you don't, then lightly grease and flour your tin. 

Remove the shortcrust pastry from the fridge and flour your work surface. Roll out the pastry 2-3mm thick and line the tin, leaving an overhang of pastry. Prick the bottoms of your pastry with a fork a few times. Place some greaseproof paper on top and fill with baking beans. Now place the pastry tin in your oven and cook for 15 minutes. After the 15 minutes remove baking paper and baking beans and leave pastry tin for another 8 minutes in the oven. Remove from the oven and allow to cool. Afterwards trim the edges and lift out onto a cooling rack.

Melt the chocolate in a bain marie (water bath). Brush the bottom of the tart with melted chocolate and let it cool.

For the dark berry filling: Heat up berries in a pot with 100 ml water. Add rice syrup, chopped thai basil, coconut milk and juice of half a lime and bring to a boil. Take off the heat and blend until smooth with a highspeed blender. 

Let the gelatine soak in cold water for about 8 minutes. 

In a small bowl mix corn starch with 2 tbsp of cold water. Put the berry mix back on heat and stir in the corn starch. Bring it quickly to a boil and take it off the heat. Squeeze the water out of the gelatine and add to the berry mix. Quickly stir in the gelatine in your hot berry mix. Let it cool down for 15 minutes and then fill your tart with the berry mixture. Let the tart cool for at least for hours or even better over night. 

When your tart is ready and the berry mixture is firm decorate it with berries and little thai basil leafs.