Whole-Wheat Beet Fougasse

Stir water and salt in the bowl of a stand mixer until dissolved. Add flour, beet, starter, oil and 1 teaspoon coriander seeds. Mix on low speed with a dough hook until the dough is completely mixed, 2 to 4 minutes. Cover with plastic wrap and let the dough rest at room temperature for 20 minutes.

Knead the dough on medium speed until smooth and pulling away from the sides of the bowl, 4 to 5 minutes. Cover and let rise at room temperature for 1 1/2 hours, folding the dough over every 30 minutes. Cover and refrigerate for 8 to 24 hours.

Place a pizza stone in the oven; preheat to 500 degrees F and let the stone heat for 20 minutes.

Turn the dough out onto a well-floured work surface and divide it in half. Cover one piece with plastic wrap. Lift the other piece onto a lightly floured pizza peel using floured hands and a floured bench scraper. Stretch it out into a 7-by-10-inch rectangle, about 1/2 inch thick.

Use the bench scraper or a sharp paring knife to cut three or four 2-inch-long diagonal slits on each long side of the rectangle, leaving about 1 inch of dough still connected at each end (see Tip). Generously dust the cuts with flour and use your fingers to open them up. Sprinkle with 1 teaspoon coriander seeds.

Gently shake the dough on the peel to see if it slides freely. If not, lift the dough and add another light dusting of flour wherever it's sticking. Then slide the dough onto the hot pizza stone. Bake for 10 minutes.

Reduce oven temperature to 475 degrees. Continue baking until the bread is browned on the bottom and sounds hollow when tapped, about 15 minutes. Transfer the bread to a wire rack.

Increase oven temperature to 500 degrees. Form and bake the remaining dough.