Toast the coriander seeds and fenugreek in a pan for a few minutes lightly.
Saute onions, garlic, celery and carrots in olive oil, add the roasted fenugreek and coriander seeds along with the chopped green chilli.
Infuse the prunes in balsamic vinegar in a pan.
Soak beans overnight or cook beans for 2 minutes in plenty of water and allow it to sit for one hour.
Drain water from beans and add plenty of fresh water to cover with onion, carrots and celery.
Cover and simmer for about one hour, until beans are tender, but not mushy. Drain and set aside.
Simmer the prunes in 1/3 cup of the vinegar for 20 minutes.
With food processor running, put garlic through tube.
Add remaining vinegar, tamarind paste, hot pepper flakes, coriander seed, fenugreek, olive oil, prunes and vinegar and process to a paste.
Add the cilantro and process to chop fine.
Season with salt and pepper.
Stir into warm beans.