Step 1. Finely dice the onions and place them into a bowl with three cups of cold water and 2 teaspoons of ground salt. Leave to soak for about 5mins drain for another 5mins through a sieve.
Step 2. Then squeeze out any remaining water through a muslin cloth (I use my hands).
Step 3. Place onion and all other ingredients into a small food processor and blend into a a coarse paste.