In a large mixing bowl combine 3 cups all-purpose flour, 1 3/4 teaspoons coarse sea salt, and 1/2 teaspoon active dry yeast; stir to distribute.
Add 1 1/2 cups warm water and stir with a wooden spoon until a sticky, shaggy dough forms.
Cover the bowl with plastic wrap and let the dough rise at room temperature for 12 to 18 hours until bubbly and doubled in size.
About 30 minutes before baking, preheat the oven to 450°F (230°C) with a cast-iron pot and its lid inside.
Lightly flour a work surface and turn the dough out onto it; shape it gently into a round ball on a piece of parchment paper and cover loosely with plastic wrap while the pot heats.
Carefully remove the hot pot from the oven, lift the parchment with the dough and place both into the pot, cover with the lid, and return to the oven.
Bake covered for 30 minutes, then remove the lid and bake uncovered for an additional 12 to 15 minutes until the crust is deep golden brown.
Remove the bread from the pot and cool on a wire rack before slicing.