This is the simplest sourdough recipe, with just a starter, strong white flour, water and salt. No seeds, no flaxseed, no bells & whistles.
The important thing is the careful folding of the dough - there are a ton of YouTube videos on the subject, and it doesn't matter at all if you fold it over in the middle, or in thirds, or an a full moon with a black cat in the kitchen. The main thing is that you fold every half an hour in the first 3 hours of the process, and that you fold and shape after the two rests.
If you follow that, you can't go wrong. Make sure your dough hydration is right - it should look like all the sourdough you see in YouTube folding videos, so I won't bother adding video # 127.
Depending on how hydrated your sourdough starter is, you might have to vary the amount of water you add. You want a hydration of around 75%.
Combine flour, starter, salt and water just until there is no more dry flour left, and and let them autolyse for 30 minutes. This means you just let the mixed up ingredients sit.
Then mix up the ingredients until they are properly combined, and fold three times every half hour for 3 hours. Then let rest for 2 hours. The photo on the right shows the dough after three hours of folding every 30 minutes.
Take out of your bowl and put onto floured surface. Fold another three times, shape into a tight round, and cover it with a bowl for 30 minutes bench rest.
Fold once more, shape again.
Put into your proving basket with the seam up, pre-heat the oven to 230 degrees, and let the dough sit for a final rise of 30 - 60 minutes whilst the oven is heating up.
Turn out of the proving basket onto your baking tray and score the top with a sharp knife.
There are lots of different recipes for this type of bread out there, and lots of people use Dutch ovens or Le Creuset pans. You don't need all that, as you can see in the photo above, baked on a simple tray in the oven is just fine.