Mix flour, salt and baking soda in a bowl, then add the whey and knead into a soft dough that no longer sticks, otherwise add a little more flour. Then immediately form 6 rolls and place on a baking sheet lined with baking paper or a baking rack.
Score the rolls lengthways with a knife or the edge of a spatula and spread a thin layer of water. Put the tray or the grid in the oven preheated to 190 ° C (convection) with a cup of water on the base and bake for about 17 minutes.
Then switch off the oven and let the rolls stand for another 2 minutes. The rolls still taste warm, but also the next day!