Grate the courgettes and squeeze out as much moisture as possible with your hands or a clean tea towel - this is the key to crispy fritters.
Put the grated courgette in a bowl with the egg, flour, cheese, spring onion, herbs and a good pinch of salt and pepper. Mix well.
Heat the oil in a large frying pan over medium heat. Drop tablespoons of the mixture into the pan and flatten slightly.
Cook for 3-4 minutes on each side until golden and crispy. You may need to do this in batches.
Drain on kitchen paper and serve with a dollop of natural yoghurt.