Cut the cauliflower into bite-size florets. Set aside.
Sift the flour and spices into a bowl, then stir in the 1⁄2 teaspoon salt and make a well in the centre.
Combine 50ml/2fl oz water with the beaten egg, and gradually pour into the well, whisking to make a smooth batter. Cover and leave to rest for 30 minutes.
Fill a deep heavy pan a third full with oil, and heat until a cube of bread browns in 15 seconds.
Holding the florets by the stem, dip into the batter. Deep-fry in batches for 3–4 minutes until golden. Remove with a slotted spoon, and drain on kitchen paper. Serve hot.