Place the red peppers, onion and tomatoes in a food processor and chop them finely. Put them into a large saucepan with the water and boil them until they get soft. Drain the mix and then add the precooked chickpeas and puree them in a food processor or blender.
Place the vegetable puree into a large bowl and then add the active dry yeast, plain yogurt, olive oil, mint, oregano, salt, red hot pepper flakes and mix them together.
Add the flour little by little to the mixture until a thick dough forms. Knead the dough for about 15 minutes. If the dough feels dry, you can add little water.
Transfer the dough to a big bowl; cover the bowl with a tea towel and leave to stand for 5 to 6 days for the dough to get fermented.
After 5 to 6 days passed, the dough will no longer rise and this means; it is ready for the next step. The dough may smell a little sour but don't worry, this is the part of the fermentation process.
Divide the dough into small balls/patties. Lay them on a dry cloth or non-stick baking paper. Leave the small patties in a dry place until one side of the patties is completely dry and then flip the patties over and allow the other sides to dry. This may take 2-3 days to all patties get dry enough and ready to get crumble.
Once the patties are dry, crumble them up until the pieces are small enough to put through a food processor or fine sieve.
Once you have fine powder, spread it out on the large trays and continue to dry it a day or two. During this time mix the powder with your hands occasionally to get air flow inside the powder and help to dry.
Keep the Tarhana powder in an airtight container to be added to your soup later.