Starter - mix the yeast with one cup of warm water; keep until rises; or use sourdough starter.
Combine in a large container the teff and barley flour with cold water or mix lightly in a blender.
Add the starter and mix it well; add water generously; cover it tight; keep it outside to ferment;
The second day, pour and discard the water; add same amount of fresh water to the dough; keep it tight.
The third day, pour and discard the water; blend the self-rising flour with three cups of cold water; mix it with the fermented dough; add water as required. This time it should be thinner than pancake dough. Keep it outside for 15 minutes to rise.
Warm a flat pancake pan, or skillet, or a specialized electric stove; pour the dough in circle shape in small amount; bake it for 30 -45 seconds.
Depending on the size of skillet, you will get 20 to 30 injeras.
If less sour taste preferred, bake it the second day.