Chop the onion, celery and carrots.
Heat the oil in a large pan, add the chopped vegetables and cook until soft.
Add the garlic and the spices, stir for 1 minute.
Drain the beans and add to the pan. Pour in the stock and chopped tomatoes.
Meanwhile, cut the pepper into small cubes, then add to the beans.
Bring to the boil, cook for 15-20 minutes. When the sauce is thick and the vegetables are tender, turn off the heat.
Chop the coriander, stir half of it in with the beans.
Serve with coriander sprinkled on top - and a couple of slices of onion (and a spoonful of yoghurt if you like).