Combine the water and sea salt in a mixing bowl, stir together to dissolve. Add your starter and stir to combine.
Add your flour and fold in with a spoon or spatula. Mix until it becomes a rough dough ball.
Cover the dough in the mixing bowl with a cotton cloth and set aside on your counter for the day, at least 8 hours.
In the evening, wet your hands slightly and pull the sides of the dough gently off the bowl and fold it over itself. Pick up the dough and tuck the sides under until you have a slightly better round shape. The dough will be quite sticky and you may need to re-wet your hands.
In a medium sized bowl put a cotton cloth and dust lightly with flour. Place your loaf round-side down into the floured cloth and then sprinkle some flour on the underside as well. Tuck the cloth over the dough so it's covered. Let rest in the fridge overnight.
The next day, preheat your oven to 450F and add a small pot of water to the back corner of your stove. Make sure it is an oven-safe container and I put about 1 quart of water in mine. This will create steam to give the bread a wonderful crust.
Take your loaf out of the fridge and flip it over into a metal baking pan. Using a sharp knife, cut an X pattern into the top of your loaf.
Bake your loaf in the steamy oven for 40 minutes. Then remove and let rest for 1 hour before slicing. Serve & enjoy!