Finely chop the onion, garlic, ginger and chilli pepper. Fry in the oil for a couple of minutes on medium heat - you don't want to burn them. After 1 minute, add the tumeric, ground coriander and ground cumin.
Chop up the squid, and add the vinegar to it. Add to the frying pan, together with the salt, finely chopped tomatoes and red pepper. Stew for 15 minutes.
Sprinkle with the chopped coriander leaves and serve with rice.