Chop the onion, garlic, then thinly slice the red pepper. Peel and dice the carrot and sweet potato.
Heat the oil in a large, heavy-based saucepan and cook the onion until tender. Add the spices and garlic, stir for 30 seconds, then add the tomato purée and stir again for a few seconds.
Add the tinned tomatoes and stock. Put the lid on, bring to the boil and cook for 15 minutes over low heat.
Add the drained chickpeas and corn. If you’re using cooked or grilled corn on the cob, carefully cut off the kernels with a knife and add these to the stew. Cook for 5 minutes.
Add the spinach (or kale) and cook for another 2-3 minutes.
Cut the fish fillets into bite-sized pieces and add these to the stew. Cook for 5 minutes under cover. Don't overcook the fish!
Taste the stew, season with salt and pepper, if needed.
Serve with coriander leaves scattered on top.