Combine the flour,salt and yeast in a mixing bowl.
Add the oil and water and mix until roughly combined.(If you have a mixer with a dough hook, beat on lowest speed for two minutes).
Tip onto a clear (unfloured) work surface and knead for about 10 to 15 minutes until the dough is smooth and elastic. (If you using a mxer,switch the dough hook up to second lowest speed and mix for 7 minutes).
Shape the dough into a ball,place in a lightly oiled bowl, sprinkle with semonlina and cover with a clean tea towel. Leave to rise and warm in a draught-free place for about one hour or until doubled in size.
Slide an upturned oven tray into the middle level of the oven (this will act as your pizza stone) and preheat the oven 240 degrees c.
Once risen, place the dough on a lightly floured surface and break into three (for American style pizza pies) or five pieces (for ultra thin pizza bases), shape each into a ball, cover with the tea towel and leave to rise for ten minutes.
Roll or stretch each piece of dough into a pizza base; place on an oiled pizza tray or baking sheet.
Brush the edges of the pizza base with olive oil and spread the bases with tomato sauce (unless you making a white pizza, in which case omit the sauce), leaving a 1 cm border around the edge. Sprinkle a scant layer of grated mozzarella before adding the other toppings and then add some mozzarella over that.
Bake for ten minutes and serve immediately