The night before, feed your starter at a 1:4:4 ratio (starter:water:flour).
Roast the garlic: top sliced off, drizzled with olive oil, sprinkled with sea salt, wrapped in foil, roasted until soft and deeply golden. Cool, then mash.
Mix the flour, water, and starter until no dry flour remains. Rest 30 minutes.
Add the salt and mix in fully.
First set of folds: stretch-and-folds.
Second set (30 minutes later): coil folds, working in the mashed roasted garlic and herbs.
Third and fourth sets: coil folds, 30 minutes apart.
Continue bulk fermentation until well risen and jiggly, about 11 hours total at a cool room temperature (~20°C).
Preshape, rest 20–30 minutes, then final shape into a banneton.
Cold proof in the fridge for 14 hours.
Preheat oven with a Dutch oven inside to 235°C. Score the loaf.
Bake covered for 25 minutes.
Bake uncovered at 220°C for 25 more minutes.
Cool on a wire rack at least 30 minutes before slicing.