In a bowl, mix flour, semolina, salt and yeast. Make a dip in the middle, pour in oil, water, then stir and squeeze everything together (hands are easiest for this). The dough should feel very sticky (pic 1). When it is well mixed, cover and leave for 15 mins.
Tip the dough on to a lightly oiled work surface and rub your hands and the inside of the bowl with oil. Knead the dough about 12 times only, giving it a quarter turn each time you knead. Tuck the ends under so it is the shape of a ball and lay it in the bowl, seam side down. Cover and leave for 10 mins. Repeat the kneading and leaving for 10 mins again, then knead and leave for 15 mins, oiling the surface and your hands each time.
In between kneadings make the sauce for the topping. Drain the tomatoes and tip them into a bowl. Snip them into small pieces with scissors (pic 2). Stir in garlic, tomato purée, and seasoning. Set aside. Brush a baking sheet with oil and sprinkle with a little semolina. Heat oven to 240C/fan 220C/gas 9.
When the dough is ready, cut in half and put one half onto a lightly fl oured surface. Knead 4-5 times to squash out any air bubbles, then roll it out. At the point where it just keeps springing back, brush off the fl our from the work surface and rub on a little oil. This makes it easier to roll. Continue to roll out until you have a 28cm circle, pulling it into shape as well. Lift it onto the baking sheet (it’s easier if you drape it over a rolling pin).
Drain the mozzarella, then pat dry with kitchen paper. Brush the dough with olive oil, then spread half the sauce over, almost up to the edge. Scatter over half the basil, then tear up one mozzarella ball and scatter over the basil (pic 3). Grate over pepper and drizzle with a little oil. Bake for 12-15 mins, until the topping is bubbling and the dough is going brown. Repeat with the remaining dough and toppings. To serve, scatter with parmesan shavings, rocket leaves and drizzle with oil.