In a large mixing bowl, combine the warm water and instant yeast. Let sit for about 5 minutes until the yeast begins to froth.

Add the all-purpose flour and sea salt to the yeast mixture. Mix with a wooden spoon until a shaggy dough forms.

Cover the bowl with a clean kitchen towel or plastic wrap and let the dough rest for 1 hour at room temperature. It will rise and become bubbly.

After the resting period, lightly flour a clean surface. Turn the dough out onto the surface, and with floured hands, gently stretch and fold the dough over itself a few times to shape it.

Divide the dough into two portions. Gently shape each portion into a rectangle and place them on a parchment-lined baking sheet.

Cover the shaped dough with a towel and allow them to rise for another 30 minutes.

Preheat the oven to 425°F (220°C) during the last 15 minutes of the second rise.

Once the dough has risen, dust the tops lightly with flour. Place the baking sheet in the oven and bake for 20-30 minutes, or until the crust is golden brown and the bread sounds hollow when tapped on the bottom.

Remove the ciabatta from the oven and let it cool on a cooling rack for at least 15 minutes before slicing.