Place the warm water, yeast and sugar in a large bowl, stir, then leave to stand for a few minutes. It will start to froth on top.
Next, add the oil to the bowl and half of the flour. Use a wooden spoon or dough handle to mix the flour into a dough. Now sprinkle in the remaining flour and the cornmeal and salt. Knead the dough with your hands for a minute until your form a soft, smooth ball. Cover with a damp, clean tea towel and leave in a warm place to rise for 30 minutes. After 30 minutes, sprinkle some flour over the dough and knead for a further 2 minutes. Now replace the tea towel and leave the rise for another 30 minutes.
Once the dough has risen, knock out any air bubbles by gently kneading. Dust a clean, flat surface with flour and place the dough on to it. Cut the dough into 2 equal pieces, replacing one in the bowl and the other on the flat surface, ready to be formed into a pizza base.
Using your hands, gently ease the dough into a 10-12 inch rectangle, being careful not to make it too thin and tear. Alternatively, you can use a rolling pin for this. Dust with flour to prevent sticking.
Sprinkle flour onto a baking tray (to prevent sticking) before placing the pizza base onto it. Repeat the last step with the other dough portion you kept in the bowl so that you now have 2 pizza bases ready for baking. Bake in a preheated oven at 180 degrees C for about 15 minutes until golden.