Sauté the onion and fennel gently in a large non-stick pan until softened, using a little of the vegetable stock to stop them from sticking.
Add the tomatoes and continue to cook for 5 minutes until they start to break down.
Add the garlic, tomato purée, chilli powder and smoked paprika and cook for a couple of minutes, stirring.
Add the beans and stock, bring to the boil then reduce the heat and simmer gently for 20 minutes. The liquid will reduce slightly. Add the cabbage and cook for 5 minutes, until just tender.
Meanwhile, make the salsa verde – you will need a food processor or stick blender to make it. Put the coriander, mint, capers, mustard, lemon juice, red wine vinegar and extra virgin olive oil with 2 tbsp cold water into a food processor and pulse until you have a rough sauce (it should not be completely smooth).
Serve the bean casserole with the salsa verde on the side to spoon over and with rice, pasta or crusty bread.
Notes
You could make this casserole with any mix of beans that you like.
Instead of cabbage you could add spinach, baby kale or other leafy greens at the end.
To freeze, make the stew but do not add the cabbage. Defrost overnight in the fridge, reheat, then add the cabbage and cook for 5 minutes. The salsa verde can also be frozen. Defrost in the fridge overnight and bring to room temperature before serving.