Dry roast the cumin seeds in a non-stick pan and shake over a moderate heat until fragrant. Allow the cumin to to cool slightly then grind the seeds with a pestle and mortar.
Heat the oil in a pan and add the onions and garlic and cook until soft. Add the cumin, chilli, and paprika and cook for a further minute or two.
Add the canned tomatoes, oregano and vinegar and rinse the tomato cans out in a little water (about ½ cup each) adding that to the pan too. Add the beans and cook gently for about 40 minutes) partially covered, adding more liquid is necessary.
Grate the cucumber into the ricotta and yoghurt and stir to combine. Stir through the fresh coriander and season with black pepper.
Serve with baby spinach, chopped fresh tomato, sliced avocado and wholemeal pitta pockets.