To make the dough, simply mix all the pizza base ingredients in a large bowl, till you have a wet, shaggy dough. Add two more teaspoons of water if the dough feels a little dry. You do not need to form a ball of dough, or bother with making it smooth. Simply mix it up, making sure all the flour is moistened, cover with clingfilm and leave to rise at room temperature for 12 to 16 hours.
After 12 to 16 hours, the dough should have doubled, look fermented and have bubbles on the base and smell slightly sour. It should also feel very soft and sticky and a little wet. In hot weather, it is best to put the bowl in the fridge if you're not ready to bake yet, to prevent the dough from getting over fermented once it has doubled, although make sure you don't postpone the baking beyond a couple of hours.
About half an hour before you begin forming the dough into pizzas, preheat the oven to 250 C (usually its highest temp, as the oven needs to be hot hot hot) and lightly flour a non-stick baking pan. If you don't have one, line your baking tray wth a silicone mat as this dough tends to stick.
While the oven is preheating, get your toppings ready.
Now, cut the dough into two and scrape one half out onto the prepared pan using floured fingertips.
Stretch and pull the dough to a roughly round shape, about 10 inches wide. It will be sticky and a little hard to work with, but it does work out in the end. You can also make a rectangular pizza, shape no bar! Don't stretch the dough too thin, because it needs to be able to hold the toppings.
Spread half the pizza sauce on the base, leaving about half an inch of a border on the edge of the dough. Top with half of the mushrooms and veggies, scattering them in an even layer over the sauce. Turn the edges of the dough up to form a crust.
Bake for 20 to 25 minutes until the crust has browned lightly and the veggies have roasted and blistered slightly. Rotate the tray as needed if one side is browning more than the other. Now top with half the cheese, and bake for 5 to 10 minutes until it is melted through, making sure you don't let it get too brown or it might lose its stretchiness. At this point the edges of the pizza will also brown further and become crispy. Slice and serve hot hot hot. Repeat with the remaining dough and toppings. Baked pizzas can be stored in the fridge for 2 days and reheated in the oven. They can also be frozen. Happy eating!