Heat a little olive oil in a large, deep pan. Add the sliced onion and sauté gently for 5 minutes, until soft and starting to caramelise.
Add the garlic, diced carrot and sweet potato. Stir and cook for 2 minutes.
Sprinkle in the oregano, smoked paprika, cumin and chilli flakes. Stir well to coat the vegetables in the spices.
Add the tomato purée, tinned tomatoes, a pinch of salt and pepper, then bring to the boil.
Reduce to a gentle simmer and cook for 10 minutes.
Stir in the kale and green beans, then cook for another 5 minutes.
Meanwhile, cut the cod into bite-sized chunks.
Add the cod pieces to the pot, season again if needed, cover with a lid and cook for 5 minutes, or until the fish is just cooked through. (Make sure, you don’t overcook the fish - it should be opaque and flake easily.)
Turn off the heat and let the dish rest, covered, for 2 minutes.
Finish with chopped parsley or coriander and serve immediately.