For the overnight sourdough:
1. Combine sourdough starter, water and salt. Whisk to combine. Add flour; stir into starter mixture.
2. Finish mixing by hand, folding mixture until it forms a rough ball. Cover with plastic wrap or a damp towel and let rest 45-60 minutes.
3. Over the next few hours, give the dough a stretch & fold about every 45 minutes or so. Plan to stretch & fold four times.
4. To stretch the dough, pull dough from one side and give it a long stretch, folding the dough back to the middle. Turn the bowl a quarter turn, stretch again and fold back to the middle. Repeat on all four sides, cover dough back up, and allow to rest again until the next stretch & fold.
5. Once you've completed all the stretches, put the dough in the refrigerator and allow it to sit overnight.
For the garlic herb filling:
1. Combine soft butter, garlic, and herbs together in a small bowl. Have your cheese ready in a separate bowl.
1. The next morning, pull your dough out of the fridge and allow it to warm up a bit, about an hour depending on the temperature of your house. This is a good time to prepare the filling.
2. Roll dough out on a lightly floured surface into a rectangle that's roughly 12 x 18 inches. Spread with garlic butter, leaving about 1/2 inch space around all the edges. Sprinkle with cheese.
3. Starting on one of the long sides, roll the dough up just like you would a cinnamon roll. Start from the center and work out to the edges as you go, making sure to keep it fairly tight. Once fully rolled, pinch the seams together.
4. Using a sharp chef's knife or a bench scraper, slice the roll in half lengthwise almost to the top, exposing the interior swirl. Leave about an inch at the top so the roll is still one piece. Gently twist the two sides of the roll around each other to make a simple braid, tucking the end under.
5. Place one end of the twist down on a baking sheet lined with parchment paper. Swirl the twist around itself, making a simple spiral, and tuck the end under. Cover with a damp kitchen towel and allow to rest about 2 hours. Dough should rise and get puffy.
6. Place your dutch oven and lid in the oven and preheat oven to 450° F. When oven comes to temperature, carefully lift your parchment paper with your sourdough twist and lower it into the hot dutch oven. Cut away any excess parchment paper, put the lid back on, and bake covered for 25 minutes.
7. Remove lid from dutch oven and continue to bake uncovered for another 25 minutes, or until bread is golden and cooked through. The best way to tell if bread is done is to take its temperature with a meat thermometer - it should be about 205 - 215° F.
8. Remove from oven and gently lift bread out of dutch oven, using the parchment paper as handles. Allow to cool completely before slicing - if you slice into it too early, you could end up with a gummy texture!