For the tart

1. Beat the margarine until soft using the K-attachment on your food processor or the dough kneader attachment on your hand mixer.
2. Add the egg and continue beating.
3. Add the almond powder and continue beating. Finally, add the pastry flour, the Zùsto and the pinch of salt. Let the food processor continue to knead until you get a firm ball (or continue to knead with your hands).
4. Wrap the dough in cling film and leave to rest in the fridge for 2 hours.
5. Grease a round baking tin with margarine and dust with flour. Preheat the oven to 180°C.
6. Liberally sprinkle flour over your work surface and rolling pin and roll out the dough. Move the dough to the baking tin and cut away the excess dough (you will have 1/4 of the dough left). Place baking paper in it and fill with the baking beads.
7. Bake it blind for 10 mins (or longer, depending on the tart recipe) in the preheated oven.

For the chocolate and walnut filling

1. Crush the walnuts in a chopper or blender and add 100 g Zùsto. 
2. Dissolve the coffee in 1 tbsp hot water and set aside.
3. Melt the chocolate in a bain-marie or in the microwave on a low setting (600W and melt for bursts of 30 seconds, stirring the chocolate between each burst). Set aside.
4. Beat the eggs together with 50 g Zùsto until frothy. Add the liquid margarine, the coffee and the melted chocolate. 
5. Finally, add the dry ingredients (walnut crumbs mixed with Zùsto). 
6. Pour the batter into the tin and bake the tart for 20 to 25 mins in