Heat 2 tbsp oil in a frying pan and fry the onions for 4-5 minutes until golden, add the cumin and cook for 1 minute. Place in a food processor with the chickpeas, coriander, 2 tbsp oil and seasoning and mix to a coarse purée. Stir in the oats, divide into 16 and mould into balls.
Heat the remaining oil in the frying pan and fry the dumplings for 3 minutes, remove and keep warm. Add the passata to the pan with 200ml water and bring to the boil and simmer for 2 minutes. Pour the sauce over the dumplings and serve.
These dumplings can be served cold with a soured cream and chive dip and salad as an alternative.