For the dough, crumble the yeast and dissolve together with the salt and the sugar in 220ml lukewarm water. Add the flour and mix to a smooth dough. Cover and leave to stand for 1 hour.
Roll out the dough on a floured surface to a 40 x 30cm rectangle.
Wash the basil for the pesto and shake dry.
Place the basil, pine nuts, Parmesan, peeled clove of garlic and the olive oil in a blender and blitz to a pesto.
Spread the pesto on the rolled dough.
Fold the longer side of the dough rectangle over the pesto filling and roll up.
Wind the dough roll into a large snail and place on a baking tray lined with baking paper. Cover with a damp tea towel and leave to rest for 30 minutes. Preheat the oven to 200°C (180°C fan, gas 6) and bake for 45 minutes until golden brown. Allow to cool and serve in slices.