Place the Pizza Stone or a flat cooking surface on the cold barbecue and pre-heat with the lid on for a few minutes while you assemble the pizza.
Chop the pistachio nuts roughly and slice the strawberries and bananas. Roll out the pizza dough and form into a round pizza base.
Sprinkle some flour on the pizza stone, the add the pizza base and replace the lid on the BBQ. Bake until nice and crispy (for about 4 minutes). Remove the pizza from the barbecue and spread the base with some Nutella.
Sprinkle the chopped pistachio nuts on top along with the marshmallows then put the pizza back on the pizza stone, put the lid on and cook for another couple of minutes or until the marshmallows are softened and started to melt a little.
Remove the pizza from the barbecue and garnish with the strawberry, banana and a dusting of icing sugar.