FOR THE DOUGH: Whisk flour, yeast, and pepper together in mixer bowl. Stir water into sponge. Slowly add sponge mixture to flour and mix until dough forms. Let rest for 20 minutes.

Add salt and knead on medium-low until dough is smooth and elastic, about 5 minutes. Gradually add cheddar until just incorporated.

Transfer dough to greased bowl, cover, and let rise for 30 minutes.

Fold dough over itself several times then let rise for 30 minutes. Repeat folding and rising for a total of 4 sets.

Mist a towel with water and dust a colander with flour. Shape dough, roll in remaining cheddar, and place seam side up in colander.

Cover and let rise until doubled in size, about 30 minutes to 1 hour.

Preheat oven to 450°F, placing baking stone in the oven with disposal pie plates filled with lava rocks.

Dust loaf with flour and invert onto parchment. Cut slashes on top of loaf.

Pour boiling water into lava rocks to create steam, then bake loaf until golden brown and cooked through. Cool before serving.