Put the flour in a bowl with salt, grains and apple cider vinegar. Crumble the yeast in the warm water (e.g. in a measuring beaker) and dissolve in it while stirring. Add the yeast water to the flour mixture while stirring and knead the dough well for at least 3 minutes.
Fill into a greased pan (I always use a loaf pan) and bake in the oven for 1 hour.
The bread can be varied a lot. It always tastes different depending on the type of flour and grains.
I think you could do it without grains (feel free to give feedback) but because we love grains this is a MUST for us.
Our mixture mostly consists of pure rye or spelled flour and sometimes half-half, and our grain mixture is always sunflower seeds, pumpkin seeds, sesame seeds and some psyllium husks.