Chop the onion, carrots and celery. Heat a couple of tablespoons of water in the base of a medium-sized pan and add the veg with a pinch of salt. Sauté on a medium heat for 5 minutes, stirring regularly so the veggies don't stick.
Whilst the veg are cooking, chop the peppers and garlic. Add the peppers to the pan with a little extra water if needed and cook for a couple of minutes, then add the garlic. Cook for another minute.
Pour the tinned tomatoes into the veg and add the spices. Stir well. Pop on the lid and simmer for 15 minutes until the veggies are soft.
Stir in the drained beans and the tomato purée and cook for another 5 minutes. Add a little water to the pan if the mix is too thick - I like a good amount of sauce!
Turn off the heat, season with salt and pepper and stir in the chopped fresh coriander or spinach. Serve on a baked potato, with wholegrain rice or wholewheat wraps.