Mix together ripe/active sourdough starter with all-purpose or bread flour and water. Cover loosely and let sit 3-4 hours at 78-80°F until doubled, bubbly & peaked.
In a large bowl, combine the ripe levain, water, whole wheat flour, bread flour, and salt. Use a dough whisk or spoon to mix until fully combined and a sticky dough forms. Cover and let the dough rest for 30 minutes.
Perform a series of 'stretch and folds' over the next 1 ½ hours, adding in shredded Asiago cheese during this process.
Cover the dough and let rise for 2-2.5 more hours at 78ºF.
Tip the bowl upside down, allowing the dough to fall onto a clean counter surface. Pre-shape the dough and let it rest uncovered for about 30 minutes.
Prepare a 9 by 5 pan with parchment paper. Shape the dough and place it into the prepared pan.
Cover the dough and refrigerate overnight or up to 14-20 hours.
Preheat the oven to 450°F. Boil the dough for about 1 minute on each side.
Top the dough with Asiago cheese and score it.
Bake for 30 minutes, then reduce the temperature to 400ºF and continue baking for 15-20 minutes until baked through.
