Whisk together kefir and sourdough starter.Add sifted spelt flour and salt.Next, knead by hand (or in stand mixer fitted with a dough hook attachment) until the dough becomes nice and pliable and absorbs all the dry bits.Cover.Then leave in the warmest place of your house for 3 to 4 hours. The goal is not to sour or raise the dough, but to condition, soften, and strengthen it.Sprinkle the dough with flour. I use all-purpose spelt flour at this point because whole grain is a bit rough for rolling.Give it a couple of hand kneads.Then transfer to a well floured work surface.Preheat a large cast iron skillet.Divide the dough in 12 pieces. Cover the pieces you are not using, to prevent drying.Roll each piece out to â…›" thick circles.Slightly stretch it by hand when you transfer it to the skillet. This helps to prevent air pockets.Then cook each lavash on medium to medium high heat for a minute or less.Flip over.Adjust heat as needed. It will take some practice to find out the best setting for you. You want lavash breads to have dark spots. If the spots don't appear, the skillet is not hot enough. That would make breads too brittle.Finally, once cooked, cool lavash between 2 towels to prevent moisture from escaping.