For the cauliflower fritters, bring a pan of water to the boil. Add the cauliflower florets and boil for 3-4 minutes, or until just tender. Drain well, then refresh in cold water and drain again. Set aside.
In a bowl, beat the egg and water together. Add the salt and flour and beat until the mixture forms a smooth batter.
Heat the vegetable oil in a deep fat fryer set to 180C. Alternatively, pour the vegetable oil into a deep, heavy-based pan so that it reaches two-thirds of the way up the pan and heat until a breadcrumb sizzles and turns brown when dropped into it. (CAUTION: Hot oil can be dangerous. Do not leave unattended.) Dip the drained cauliflower florets into the batter, then carefully lower them into the hot oil, in batches if necessary. Deep fry for 3-4 mins, or until crisp and golden-brown, then carefully remove them from the oil using a slotted spoon and set aside to drain on kitchen paper. Repeat the process with any remaining cauliflower florets.
For the curried mayonnaise, mix the mayonnaise and curry paste together in a small bowl until well combined.
To serve, place a spoonful of the curried mayonnaise into the centre of each of four serving bowls. Arrange the cauliflower fritters around the curried mayonnaise. Sprinkle over the chopped coriander leaves.