In a deep pot, melt the chocolate on a low heat with sunflower oil, or you can put in a micowave.
After the chocolate is melted, add nutella,and stir nicely until you get nice homogeneous mixture.
Take aside the mixture from the cooker, and put the puffied rice flakes in the mixture.
Stir nicely,and the mixture put it on a platter coated with baking paper.
The rice chocolate put in the fridge to cool down and to get harden.
Believe me, the taste is fabulous, this chocolate I make often for my family.