Tip the sugar in a bowl and pour 350 ml in warm water. Stir well to dissolve the sugar, then mix in the yeast. Add flour, salt, 2 tablespoons olive oil and chocolate. Stir well to bring together in a ball and tip on a lightly puffed work surface and knead for 5-10 minutes until elastic, soft and less sticky. Transfer to a clean bowl, cover and set a separate set to get up in a warm place for 1-2 pm, or until it doubles in size.
