Preheat the oven to 200C/400F/Gas 6.
To make the base, in a large bowl mix the flour, water, oil and salt to form a dough.
Dust your hands with flour and shape the dough into a ball. Roll out on a floured surface into an 20cm/8in round.
Heat a small frying pan and cook for two minutes on each side.
To make the tomato sauce, place the tomatoes, olive oil and garlic in a saucepan.
Simmer until thick, then stir in the herbs. Season with salt and freshly ground black pepper.
Spread some of the tomato sauce on the pizza. Sprinkle over the bacon, mushrooms and cheese, and season with salt and freshly ground black pepper.
Bake in the oven for five minutes until the cheese has melted.