Preheat your oven to 400°F (200°C).

Slice the top quarter off the head of garlic, exposing the cloves.

Drizzle with olive oil, wrap tightly in aluminum foil, and bake for 40-45 minutes until soft and caramelized. Or use one of these cool garlic roasters.

Let it cool completely, then squeeze the roasted cloves out of their skins. Set aside.

In a large mixing bowl, whisk the warm water and active starter together.

Add the bread flour and whole wheat flour.

Mix until a shaggy dough forms and no dry flour remains. Cover and let rest for 45 minutes to autolyse.

Sprinkle the sea salt over the dough. Dimple it in with wet fingers and perform a series of stretch and folds for about 3-5 minutes until the dough builds initial tension.

Cover and rest for 30 minutes.

Turn the dough out onto a lightly misted counter. Gently stretch the dough out into a large, thin rectangle for lamination.

Smear the cooled roasted garlic cloves evenly across the surface and sprinkle with the freshly chopped rosemary.

Fold the dough into thirds (like a letter), then roll it up. Place it back in the bowl, cover, and rest for 30 minutes.

Perform 3 more sets of coil folds spaced 30 minutes apart to continue building strength.

After the last fold, let the dough rest untouched until it has increased in volume by about 40-50%, shows bubbles on the surface, and feels airy.

Turn the dough onto an un-floured surface. Use a bench scraper to shape it into a loose round.

Let it sit uncovered for 20 minutes to relax the gluten.

Lightly dust the top of the dough with rice flour. Flip it over and stitch the dough into a tight boule. Place it seam-side up into a rice-floured banneton.

Cover the banneton securely and transfer to the refrigerator for 12 to 16 hours for the cold retard.

Preheat your oven to 500°F (260°C) with a Dutch oven inside for at least 45 minutes.

Turn the dough out onto parchment paper, score it, and carefully transfer it to the hot Dutch oven. Drop an ice cube under the parchment for extra steam, cover, and bake for 20 minutes.

Remove the lid, reduce the oven temperature to 450°F (230°C), and bake for an additional 20-25 minutes until the crust is deeply caramelized.

Cool completely on a wire rack before slicing.