Put a clean tea towel in a colander over a bowl. Tip in the grated courgettes. Wring the towel several times, to squeeze out as much moisture as you can. Wash and dry the bowl and tip the courgettes back in.
Add the chopped chilli, spring onion, curry powder, ginger, coriander, gram flour and chickpeas.
Mix together well, cover and chill for at least 30 minutes.
Meanwhile, mix the zest from 1 lime into the yogurt.
Mix all the ingredients in a bowl, season and leave to stand.
Roughly shape the courgette mixture into 8 balls, then flatten into patty shapes. Heat a layer of oil in a large non-stick frying pan. Fry for 3-4 minutes on each side, until golden. Serve with a dollop of citrussy yogurt and the salsa on the side.
