1. Combine the flour, salt, and yeast together, then form a well in the centre. Add the water and 1 teaspoon of the olive oil and stir until the mixture holds together.
2. Turn onto a floured surface and knead for 7-10 minutes.
3. Put the dough into a bowl greased with olive oil, cover with cling film, and allow to rise in a warm place for 1 hour.
4. Knead the dough again for another minute or so, then form the mixture into 18 even-sized balls.
5. Coat each dough ball in a generous helping of pesto.
6. Place the dough balls into a large cake tin, cover and rise for another hour.
7. Preheat the oven to 180°C/375°F.
8. Cover the dough balls with the cheddar and mozzarella, and bake for 20-25 minutes.