1. Combine the flour, salt and yeast in a large bowl. Pour in 275ml hand hot water with the 2 tbsp oil to the dry ingredients and mix together to form a ball.
2. Turn out onto a lightly floured surface and knead for about 10 minutes, until the dough is smooth and elastic. Place in a large, lightly oiled bowl. Cover with clingfilm and leave in a warm place for about 1 hour, until the dough has doubled in size.
3. Using a floured hand, punch the risen dough to knock out the air bubbles. Turn onto a lightly floured surface and knead lightly. Roll the dough out into a circle, about 30cm diameter, or an oval. Using a rolling pin, lift the circle of dough carefully and transfer it to a baking sheet.
4. Preheat the oven to 200°C, gas mark 6. Spread the pesto on the dough base leaving about 1cm around the edge. Scatter over the tomatoes and torn mozzarella. Allow to stand until the dough has doubled in size again (about 40 minutes). Bake in the preheated oven for 20 minutes until the crust is crisp and golden. Scatter with the rocket and Parmigiano Reggiano and drizzle with the remaining oil to serve.