Finely chop two cloves of garlic. Boil the red chillies in one cup of water for five to seven minutes. Grind the red chillies and the remaining garlic to a fine paste.
Heat oil in a pan, add chopped garlic, green chillies, spring onion (keeping the greens aside) and ginger and sauté for a minute. Add the red chillies and garlic paste and continue to sauté. Add vegetable stock or water, celery, tomato ketchup and salt and stir to blend well.
Add vinegar and spring onion greens. Simmer for a minute and take off the heat. Cool and store.