1. Thinly slice fennel bulbs (a mandolin is good here). Heat a heavy based saucepan over a medium heat, add the oil and when hot add the fennel and potatoes. Stir well, add the curry paste and cook for 1 minute to release flavour. Core and roughly chop tomatoes and add with the carrots and vegetable stock. Bring to a simmer, stirring well, cover with a lid and continue simmering until the potatoes are tender, about 15 minutes.
2. Add the beans, spinach and coconut milk and simmer for a further 5 minutes. Season with salt and freshly ground black pepper. Stir through the chopped coriander.