In a big pot pour boiling water and soak the cannelloni for 4 minutes. Drain and dry well with kitchen towel.
In 2. In a big pan over medium-high heat, heat the oil and fry the cannelloni until it’s golden (about 1 minute) then take it out on kitchen paper and keep to cool completely.
Melt the chocolate in microwave and dip each sides of each cannelloni in it and dip again in the roughly crushed pistachio and set aside.
In a sauce pan whisk well together milk, flour, sugar, vanilla and egg then put over medium heat and keep stirring until it has thickened well, remove from heat and fold in the finely crushed pistachio then transfer to a piping bag.
Fill each cannelloni with the pistachio cream and arrange them in a serving plate.
Dust with icing sugar and garnish with pistachio.