In a large mixing bowl, whisk the flour, salt, and yeast together until mixed. Stir in the water until a sticky dough forms. Cover the bowl with cling film and let it rest overnight (about 12 hours) at room temperature.
In the morning, preheat the oven to 250°C / 225 C fan and cut a large round of baking paper so that it can fit in the bottom of a large cast iron pot. Place the pot - lid and all, but NOT the paper into the oven to heat up - about 30 minutes. Alternatively, place a baking tray into the oven to heat up.
Whilst the oven is heating up, scrape the dough from the bowl onto a floured work surface and shape onto a ball. Place the ball onto the baking paper and then place everything into the pot or place directly onto the baking sheet. If using the pot method; place into the oven with the lid on for 30 minutes, then remove the lid, and bake for another 15 - 20 minutes to get the outside crust golden brown and crispy. If using the baking tray method; place the baking tray into the oven along with a baking tray filled with ice cubes, to create steam and cook for 30 minutes. Transfer onto a cooling rack and let cool before slicing and eating.