Place the chick peas in a bowl with the onion, garlic, cumin, ground coriander, salt and pepper and use a pestle and mortar to lightly mash the chick peas until the mixture begins to stick together. Add the chopped coriander, if using.
Take walnut-sized portions and shape them into small, flat rounds 1cm thick. Roll the falafel in the flour so they are well coated and chill for 15-30 minutes. Heat the about 2.3cm oil in a frying pan, when hot add a few falafels and cook over a medium heat for about 5-6 minutes, turning frequently. Drain on kitchen paper.
Serve with a dip such as Mint, Yoghurt and Cucumber (see below) along with crudités sticks of cucumber and red pepper.