To make the herb yoghurt, mix everything together in a bowl, season with salt and pepper and set aside.
Fill a deep-fat fryer or a large, deep, heavy-bottomed pan two-thirds full with the oil. Heat to 180C (a cube of bread should turn brown in one minute when dropped in.) CAUTION: Hot oil can be dangerous. Do not leave unattended.
To make the fritters, place the broccoli in a bowl, add the herbs and some salt and toss well. Add the flour, baking powder and enough water to coat the broccoli in batter.
Deep-fry the fritters for 5 minutes or until golden brown. Drain on kitchen paper and serve with the herb yoghurt.