Wrap onion in a tea towel or muslin and squeeze out as much moisture as possible. Set aside. Place chickpeas, parsley, garlic, cumin, coriander, salt and bicarbonate of soda in a food processor. Process until the mixture is coarsely pureed. Mix chickpea mixture and onion together in a bowl. Stir in the flour and egg. Shape mixture into four large patties and let stand for 15 minutes.
Preheat an oven to 200 C / Gas 6.
Heat olive oil in a large, oven-safe frying pan over medium-high heat. Place the patties in the pan; cook until golden brown, about 3 minutes on each side.
Transfer pan to the preheated oven and bake until heated through, about 10 minutes.
Did not work for me. The spices were not enough for our tastes and the consistency of the mix was very wet after the egg was added despite drying the chickpeas and onions. I would not add egg if I make falafel again, as it did not seem necessary - 09 May 2016