Rub between the fingers till flour looks like crumbs.
Place it in a cling wrap and form dough.
Refrigerate it for 10 minutes.
Preheat the oven to 180 C for 10 minutes.
Roll the dough on to a floured surface.
Roll it to required size based on the tart pan.
Blind bake in the oven at 180 C for 10 minutes. (blind bake - add any dry beans to aluminum foil and place it on the tart) Remove the beans and bake for 5 minutes.
Let it cool down while filling is made.
To make Walnut Chocolate Cake:
Preheat the oven to 180C for 10 minutes.
In a mixer jar, add walnuts and sugar.
Grind it to powder.
Add all the remaining ingredients and blend.
Once everything comes together, pour it on top of the baked tart.
Top it with walnuts if needed.
Bake in oven at 180 C for 20-30 minutes, until toothpick inserted comes out clean.