Whole Wheat Feta Cheddar Seeded Sourdough Batard

Steps

1. The night before mixing, around 9 pm, feed your sourdough starter at a 1:1 ratio by weight as usual and leave it at about 75°F (24°C); it should peak, doubled and bubbly, in 6 to 8 hours.
2. Also that evening, toast all of the pumpkin seeds in a dry skillet for 3 to 4 minutes until they pop, then cool. Set aside one quarter of the pumpkin seeds and half of the sesame seeds for the crust.
3. Morning, about 7 am: in a large bowl mix the whole wheat flour, the bread flour and 360 g of the water (all but the last 30 g) until no dry bits remain. Cover and rest 45 minutes.
4. Add the peaked sourdough starter to the dough and squeeze it in with wet hands. Rest 20 minutes.
5. Sprinkle the salt over the dough with the remaining 30 g of water and squeeze until absorbed. Counting the starter, the dough is about 80% hydration and 1.4% salt.
6. Bulk rise at about 75°F (24°C) for 4 to 5 hours. During the first 2 hours, do 4 sets of stretch-and-folds 30 minutes apart.
7. At the second set of folds, spread the dough out and scatter the remaining three quarters of the pumpkin seeds, the remaining half of the sesame seeds, the flaxseed, the oregano, the crumbled feta and the cubed cheddar over it; fold and stretch until evenly spread.
8. Bulk is done when the dough has grown about 50% and feels airy, domed and jiggly, with bubbles on the sides.
9. Turn the dough onto a clean counter, pre-shape into a loose round and rest 20 minutes. Shape into a tight batard.
10. Mist the top of the batard with a little water from a spray bottle and roll it in the reserved pumpkin seeds and sesame seeds, then place it seam side up in a towel-lined banneton or bowl.
11. Cover and cold proof in the fridge overnight, 12 to 14 hours.
12. Next morning, place a Dutch oven with its lid in the oven and preheat to 475°F (245°C) for 45 minutes.
13. Turn the cold batard onto parchment, score one long slash, and lower it into the hot Dutch oven. Bake covered 20 minutes.
14. Uncover, lower the heat to 450°F (230°C) and bake 22 to 27 minutes more until deep brown and crisp and the center reads 205°F (96°C). The feta and cheddar may bubble at the surface.
15. Cool the loaf on a rack at least 1 hour before slicing into 12 slices.