Whisk 1/2 cup teff flour with 1/2 cup warm water, sugar and yeast.
Cover with a towel and let sit for an hour.

Add 1/4 cup water, salts, and vinegar and mix well.
Sprinkle the baking powder. Whisk and proceed to make the Injera.

Start up the pan on medium high heat and wait till hot.
Drizzle a teaspoon of oil. Spread the oil using a paper napkin to form a thin oil layer on all of the pan.

Make a smaller flatbread to begin with. to let the pan heat well and also get a feel for how the batter moves. Pour 2-3 Tablespoons of the batter and make the flatbread.
The batter should be a thin pancake batter. Depending on the Teff or flours used, you might need to add more water or flour if the batter is too thin(no holes develop when the flatbread cooks) or too thick(makes flatbread like a pancake). I used a 12 inch large non stick pan.
Pour 1/3 to 1/2 cup of the batter on the hot pan.

You can either pour the batter in concentric circles or pour all of it and then move the pan to spread it around. See pictures above.

Once spread, wait for a few bubbles to appear then cover the pan with a lid to steam the injera for a minute or so.

Remove lid and let cook until the center is set and not wet and the edges start to pull away. 3-5 minutes depending on the size.

Remove the Injera and let cool. The edges might feel crisp when you take it off heat but will soften once cool.