Rosemary Walnut Rye Boule

Steps

1. Toast the walnuts in a dry skillet over medium heat for 4–5 minutes until fragrant, then cool and chop roughly. Crumble the dried rosemary between your fingers.
2. Set aside about 10 g of the bread flour for dusting. In a large bowl, whisk the rye flour, the rest of the bread flour, the instant yeast, the rosemary and all but a pinch of the salt (save that pinch for the egg wash).
3. Stir the honey and olive oil into the lukewarm water, pour it over the rye and bread flour mixture and mix with a stiff spatula until no dry patches remain; the dough will be sticky, about 71% hydration and 2% salt.
4. Knead in the bowl with wet hands for 5 minutes, then fold in the walnuts until evenly spread.
5. Cover and let rise at about 75°F (24°C) for 1½–2 hours, until puffy and about 1½ times its size (rye won't fully double).
6. Dust the work surface with the reserved bread flour, turn the dough out, shape it into a tight round with wet hands, and set it seam-side down on a sheet of parchment.
7. Cover and proof at about 75°F (24°C) for 45–60 minutes, until the surface shows small cracks and the dough springs back slowly when poked. Meanwhile, place a lidded Dutch oven in the oven and preheat to 450°F (230°C) for at least 30 minutes.
8. Beat the egg with the reserved pinch of salt. Brush half the egg wash over the loaf, then score a cross on top with a sharp knife.
9. Lift the loaf by the parchment into the hot Dutch oven, cover and bake 25 minutes.
10. Uncover, brush the loaf with the remaining half of the egg wash, lower the oven to 425°F (220°C) and bake 20–25 minutes more, until deep golden and glossy and the center reads 205–210°F (96–99°C).
11. Cool the boule on a rack for at least 1½ hours before cutting into 12 slices, since rye crumb sets as it cools.