9ozpotatoes260g, peeled and diced approx ¾in/2cm dice
4 ½ozwhite cabbage130g, shredded, or light green
At least a day ahead, mix together the teff flour and the water in a bowl, cover loosely with a cloth and leave to sit at room temperature to gently ferment for 1 - 3 days (the slightly sour flavor will be stronger the longer it is left).
When ready to cook
When you are ready to cook, make the tikel gomen first and make the injera as the tikel gomen is almost ready.
For the tikel gomen, warm the oil in a pan that has a lid (skillet or deeper pan fine) over a medium heat and add the onions and carrots. Cook, stirring regularly, for around 5min, so that the onions soften but don't brown.
Add the potatoes, cabbage, turmeric, cumin, salt and pepper. Stir so the spices are mixe through, reduce the heat, cover and leave to cook around 20-30min until the potatoes are tender, stirring now and then.
When the tikel gomen is almost ready, warm a little oil in a skillet/frying pan for the injera. Pour a thin layer into the pan to cover roughly to the edge (the exact amount you need depends on the size of your pan, you can make them large or small - large is more traditional although smaller is easier to remove from the pan).
Cover the pan and allow to cook for 3-5minutes until any bubbles in the batter disappear, it's dry on top and the edges start to curl up. Use a spatula to remove from the pan and keep warm (cover with a cloth) while you cook the rest. If in doubt, it's probably better to let it cook longer to save it sticking to the pan and the flavor if it crisps slightly is quite nice, though I know not everyone's preference.
Note the tikel gomen will serve more if it's one of a number of dishes as is often served.