1. In a large mixing bowl, combine the flour, whole wheat flour, oats, water, salt, and starter. Stir/mix until a soft, shaggy dough forms (make sure all of the dry flour gets incorporated into the dough). Cover with a damp tea towel and allow this to rest 20-30 minutes.

2. Stick your hand under the dough, grab a handful, and pull it up as high as you can without breaking it. Fold the stretched dough down over the top of the whole amount. Repeat this process from different sides of the dough 4-5 times, or until the dough isn’t “loose” anymore and it begins to feel stronger, or “taut”. Cover, and allow this to rest 30 minutes.
3. Repeat the stretch and fold process, folding 3-4 times, or until the dough begins to feel stronger (harder to stretch) again. Cover, and allow to rest another 30 minutes.
4. Repeat the stretch and fold process one final time, again folding 3-4 times, or until the dough feels taut and smooth. Cover, and allow to rest 3-6 hours or until the dough is doubled or nearly doubled in bulk.

For the pre-shape (optional):

1. Turn the dough out onto a clean, unfloured work surface. Divide it into 2 equal portions, and stretch one piece of the dough out into a square. Pull the corners of the the square into the centre, and then repeat “stretching and folding” the edges into the centre (from each corner, about 3-4 more times) until the dough comes together into a smooth ball. Turn upside down, and repeat with the other section of dough. Cover, and allow these to rest 30 minutes.
2. If you choose to skip the pre-shape, you can place your shaped loaves smooth-side down into flour-dusted banneton baskets or bowls at this point.

Shape the dough:

1. Pull each pre-shaped loaf into a square again, and stretch and fold the corners into the centre again. Roll the dough into a loaf shape, and pat the outside with a clean paper towel dipped in water, to make the surface of the dough sticky. Pour the oats for the coating (1 cup) onto a large plate, and roll the sticky dough in oats to cover it. Place the loaf oat-side down into a lightly floured banneton basket or bowl* lined with a tea towel. Repeat with the second loaf.

2. Cover with a bit of plastic wrap (optional). Fold the towel over top, and place the loaves immediately into the refrigerator. Allow to rest in the fridge until the next morning.

Bake the bread:

1. The next morning, place a dutch oven into a cold oven, and preheat to 425 degrees F. Set the timer for 15 minutes.
2. Uncover the bread and remove the plastic wrap. Turn out onto a sheet of parchment paper, and score with a sharp knife or razor blade (one or two slashes is good for this recipe).
3. Once the dutch oven has been in the oven heating for 15 minutes, take it from the oven, remove the lid, and lift the bread into the hot dutch oven by the parchment paper sheet. Cover, and return to the oven for 35 minutes.
4. Remove the lid from the dutch oven, and allow the bread to bake 10 minutes more, just to brown it. Repeat with the second loaf, or save it for the next day to bake it fresh. Cool fresh bread on a wire rack. For best results, cool the bread completely before slicing into it.