Dill Garlic Walnut Whole Wheat Sourdough Batard

Steps

1. Day 1, about 8 a.m.: feed your sourdough starter with equal weights of whole wheat flour and water from your usual starter supply and keep it at about 75°F (24°C). It should peak, doubled and bubbly, in 4 to 6 hours; weigh the sourdough-starter for this loaf from it then.
2. While the starter rises, toast the walnuts in a dry skillet over medium heat for 4 to 5 minutes until fragrant, cool them and chop roughly. Chop the dill and mince the garlic, then toss the walnuts, dill and garlic together in a small bowl and set aside.
3. Set aside 10 g of the bread flour for dusting later.
4. About an hour before the starter peaks, mix the whole wheat flour, the remaining 110 g of bread flour and 360 g of the water in a large bowl until no dry patches remain. Cover and rest 1 hour (autolyse).
5. Add the sourdough-starter to the dough and squeeze and fold it in by hand until even, about 3 minutes.
6. Sprinkle the salt over the dough, add the remaining 30 g of water and 20 g of the olive oil, and squeeze and fold until absorbed and the dough feels cohesive, about 5 minutes. The dough is about 80% hydration and 2% salt, counting the starter.
7. Rest the dough 30 minutes, then spread the walnut, dill and garlic mixture over it and work it in with the first set of stretch-and-folds: lift one side of the dough, stretch it up and fold it over, turn the bowl a quarter and repeat 4 times.
8. Bulk rise covered at about 75°F (24°C) for 4 to 5 hours, doing 3 more sets of stretch-and-folds 30 minutes apart, then leaving it alone. It is ready when it has grown about 50%, looks domed and airy at the edges and jiggles when the bowl is shaken.
9. Rub the remaining 5 g of olive oil over the inside of a clean bowl and line it with a towel, or use an oval banneton, and dust the liner with half of the reserved bread flour. Dust the counter with the other half of the reserved bread flour, turn the dough onto it, pre-shape into a loose round and rest 20 minutes.
10. Shape into a batard: flatten gently, fold the top third down, fold the sides in, then roll it up tightly from the top toward you and pinch the seam. Place it seam side up in the lined bowl or banneton.
11. Cover and cold proof in the fridge for 12 to 16 hours, until it springs back slowly when poked.
12. Day 2: place a Dutch oven with its lid in the oven and preheat to 475°F (245°C) for 45 minutes.
13. Turn the cold dough onto parchment, score one long, shallow slash down its length, and lower it into the hot Dutch oven. Cover and bake 20 minutes.
14. Remove the lid, lower the oven to 450°F (230°C) and bake 22 to 25 minutes more, until the crust is deep brown and crisp and the center reads 205°F (96°C).
15. Cool the loaf on a rack for at least 2 hours before slicing into 12 slices, so the crumb sets and the crust stays crisp.