Remove the biga from the refrigerator 1 hour before you plan to make the bread. Cut it into about 10 small pieces. Cover the pieces with plastic wrap and let them sit to take off the chill.

Stir (or mix) together the flour, salt, and yeast. Add the biga pieces, mashed potatoes, and water.

Mix until the ingredients form a wet, sticky ball. Add more water or flour as necessary. Switch to the dough hook and mix for 4 to 5 minutes, or as long as it takes to create a smooth, sticky dough. The dough should clear the sides of the bowl but stick to the bottom of the bowl. Add flour or water as necessary. The dough will be very sticky.

Make a bed of flour on the counter about 8 inches square. Use a spatula dipped in water to transfer the dough to the bed of flour. Then perform the stretch-and-fold method.

Mist the top of the dough with spray oil, dust with flour, and loosely cover with plastic wrap. Let it rest for 30 minutes.

Repeat the stretch-and-fold method and mist with spray oil again, dust with additional flour and cover. Let it rest for another 30 minutes. Do this for a total of three times.

Lightly oil a large bowl and transfer the dough to the bowl. Cover the bowl with plastic wrap and let the dough ferment for 2 hours.

Dust the counter with flour. Remove the plastic wrap and with floured hands and a scraper dipped in flour, transfer the dough to the counter.

Using a metal pastry scraper dipped in flour, cut the dough into 2 pieces.

Dip your hands in flour and gently shape the dough pieces into 2 boules.

Prepare 2 proofing bowls and coat them with spray oil and generously dust the surface of the cloths with flour.

Gently transfer the dough, seam-side up, into the bowls. Mist the top of the dough with spray oil and cover the bowls with the flaps of the cloth.

Proof the loaves at room temperature for 60 to 90 minutes, or until the dough has expanded to about 1 ½ times its original size.

Preheat the oven to 500 degrees.

Prepare the cloche by greasing the bottom with coconut oil and sprinkling it with cornmeal. Soak the domed lid in water for about 15 minutes while preheating the oven to 450 degrees.

Gently transfer the dough for one loaf into the La Cloche.

Score the loaves with a pound (#) pattern using a serrated knife.

Bake the loaves for 15 minutes, check them and continue baking for another 5 to 15 minutes, or until the breads are a deep golden brown.

Remove the loaves from the oven and transfer to a cooling rack. Allow the loaves to cool for at least 40 minutes before slicing or serving.