In a large bowl, whisk together Teff Flour and Water until you have a smooth, thin batter (similar to heavy cream or thin pancake batter); adjust water a little at a time to reach that consistency.
Cover the bowl loosely with a clean cloth or plastic wrap and leave at room temperature to ferment. After 12–48 hours the batter should smell pleasantly sour and show some bubbles—longer fermentation yields a tangier flavor.
Stir the fermented batter well; if it has separated, mix back to a uniform consistency. If the batter is too thick, thin with a little more Water so it spreads easily in a hot pan.
About 10–15 minutes before cooking, stir in a small pinch of Fine Salt to taste and mix thoroughly.
Heat a nonstick skillet or a flat griddle over medium-high heat until hot. Lightly oil if your pan requires it, then reduce heat to medium.
Pour a ladleful of batter into the center of the pan and quickly swirl or tilt the pan so the batter spreads into a thin, even circle. Aim for a thin layer to encourage the characteristic holes.
Cook on the top side only: heat until many small holes form across the surface and the batter sets (the surface will no longer look wet), about 1–3 minutes depending on thickness and heat. Do not flip.
Remove the injera with a spatula and let cool on a clean cloth or plate. Repeat with remaining batter. Stack completed injera covered with a towel to keep them soft until serving.
