Whisk 1/3 (to 1/2) cup of active sourdough starter into 1 3/4 cups of lukewarm water.
Whisk 1.5 tsp salt into the starter/water mixture.
Slowly add 4 cups of bread flour to the bowl, mixing in between each cup.
Cover your bowl with a damp towel, plate or re-usable bowl cover and let rest for 30 minutes so that the flour can fully hydrate.
Either do 4 sets of stretch and folds, 30 min to 1 hour apart, OR knead your dough for 1-2 minutes. Make sure the dough is always covered when you aren't working on it.
Let the covered dough sit until it has doubled in size.
Laminate the dough by flattening it out on the counter, pressing all the bubbles out, and then folding it in thirds like a brochure. Then roll it up.
Cup the dough with your hands and spin it in circles while folding it under to create surface tension on the top of the dough and to make the pretty circle shape.
Plop your dough into a floured banneton or just a bowl with a bandanna. Pinch together the bottom so that it doesn't come apart.
Cover your bowl or banneton and let your dough sit in the fridge for 12 hours to 2 days. I think 12-24 hours is the sweet spot.
Stick your cold Dutch oven into your cold oven and pre-heat to 450 degrees Fahrenheit.
Place your chilled dough onto a piece of parchment paper or a bread sling. Cut a cross on top and put it in your Dutch oven. Spray with water and add 3 ice cubes.
Put the lid on and bake 5 minutes.
Re-cut your cross and mist with more water. Cover and bake 20 minutes.
After 20 minutes, your bread should look like a pale version of the final product. Remove the lid and bake 25 more minutes until the bread is a perfect golden brown.
Remove bread from Dutch oven and let it cool completely before cutting.