In a bowl, combine flour (ot the mix of flours), salt and yeast.
Add kefir and honey.
Stir until all flour is hydrated. Dough will be a bit sticky, that’s normal.
Cover the bowl with cling film or a lid. Place in the fridge for 12–24 hours. The longer it sits, the more flavor develops.
Preheat the oven to 470°F (240°C) with either a baking stone or a 9-inch (23cm) Dutch oven inside. In case you don't have any, simply use a baking sheet, and preheat for at least 30 minutes before baking (If using the baking stone or the baking sheet place a small pot with water at the base of the oven to create steam, the Dutch oven does not need it as the lid will create enough steam.)
Remove dough from fridge. Lightly flour your hands and surface.
Gently fold it into a rough round shape, no kneading required.
Transfer to a parchment paper. Score the bread using a bread lame or sharp knife.
Carefully transfer it to the preheated Dutch oven, baking stone, or the back of the baking sheet.
Bake for 20-25 minutes covered.
Remove cover, reduce oven temperature to 440°F (230°C).
Bake for another 15- 20 minutes without steam, until golden brown.
Let it rest on a wire rack.