In a large bowl, mix the sourdough starter with the water and the dried yeast. Mix well. Add the olive oil and mix.
Add 1/2 of the flour and mix. When that’s been incorporated, add the rest of the flour and mix well. There should be no dry pieces of flour left. Gently knead the dough for around a minute.
Place into a clean bowl with a lid or cover it with cling-wrap. Place in the refrigerator for at least 24hrs to ferment.
When you’re ready to bake, take out the dough out of the refrigerator and knock it back on a clean bench. Divide the dough into two equal portions, around 250g each. Shape the dough balls into spheres. Dust the bench with flour (bread, pizza or AP flour) and place the dough balls on top. Sprinkle a generous amount of flour on top and cover with a clean tea towel. Let the dough prove for 90 minutes.
One hour before making the pizza, turn the oven on to its highest setting with the pizza stone on the centre rack. Prepare your pizza toppings.
To shape the pizza base, gently flatten the dough ball on your floured surface. Push down with your fingers, being careful not to flatten the outside edges of the dough. The easiest way to stretch the dough is to lift it off the bench holding the outside edges and let gravity do the work while rotating the dough. Do not use a rolling pin as it takes all the air out of the dough and you wn't get that lovely risen edges on the pizza.
When you have achieved your final shape, transfer the dough to the pizza peel dusted with semolina flour. You can gently do a final shaping of the pizza base at this time.
Regardless of your other toppings, be modest in your use of the tomato sauce and do not cover the raised edges of the pizza base as you’ll want a good crust as the dough rises. Less is more when it comes to your mozzarella coverage too, as it will spread when cooking.
When your ready to bake the pizza, test that the pizza can slide on the semolina flour. You might need to lift up the edge of the pizza and add more flour if it’s sticking.
Open the oven door and place the pizza on the pizza stone and by moving the peel towards you the pizza should come free from the peel. If it’s sticking a little, give the peel a quick backwards and forwards motion to release it.
Bake the pizza for around 5 minutes and check through the glass that the edges are puffy and starting to colour. Depending on your oven, you might need a couple more minutes. If you check the pizza and it’s cooking more on one side, rotate the pizza 180˚. The pizza base should be firm and the edges should be crispy and coloured.
Allow to cool a little before cutting. You can drizzle a little olive oil on the pizza before eating.