Start the sourdough process before 9 am to allow enough time. In a large bowl, combine sourdough starter, bread flour, sea salt, and water. Knead the ingredients together until a uniform dough ball forms. Mist your clean countertop with water, wet your hands and the top of the dough, then turn the dough onto the wet surface. Scrape and rinse the bowl well, leaving it wet. Stretch and fold the dough by pulling the top over the bottom, sides over each other, and place seam side down in the bowl. Let the dough rest for 30 minutes. Repeat the misting, stretching, folding, and resting process three more times, resting 2 hours between each stretch and fold. Clean and dry your countertop, sprinkle with flour and flour your hands. Flip the dough onto the floured surface seam side up. Pre-shape the dough by gently stretching and folding, then form a circular shape with the seam side down. Sprinkle flour on top, cover with a tea towel, and let rest for 1 hour. Sprinkle more flour, flip the dough seam side up, and perform the final shaping by stretching and folding. Flour a proofing basket or bowl lined with a towel and flour. Place the shaped dough seam side up into the basket. Cover and refrigerate overnight (8-12 hours). Preheat your oven and Dutch oven with lid at 450°F. Carefully remove the hot Dutch oven, place lid aside. Place a parchment paper square on the counter, turn dough seam side down onto parchment. Score the dough with a sharp knife or scoring tool. Lift the dough using parchment corners and place into the Dutch oven. Cover with lid and bake at 450°F for 30 minutes. Remove lid and bake uncovered for an additional 20-30 minutes until golden brown. Remove bread from Dutch oven and cool at least 1 hour before slicing.