Put the onions in a large bowl and add the green chillies, chilli powder, fresh coriander, lemon juice and ajwain. Sift the chick pea flour with the salt. Heat plenty of oil in a karai-type container or a deep pan but do not let it get too hot. Gradually add the sifted flour to the onion mixutre, rubbing it in with your fingers until firm and sticky. Add the water and mix well. With your already messy fingers, put small dollops of the mixture into the oil to fry - just a few at a time or they will be soggy. The bhajia should be no bigger than 2.5cm. Do not make the sort of tennnis balls you might be used to seeing elsewhere! Fry them slowly until crisp and golden on the outside and cooked through in the centre. If the oil is too hot they will be raw and gooey inside. Drain in a sieve placed over a bowl and then serve immediately with green chutney, green coconut chutney or fresh tomato chutney.