Prepare the cauliflower and broccoli cutting it into medium-sized florets.
Cook the cauliflower and broccoli in a pan of boiling water for 2 minutes until just cooked. Drain through a colander and rinse under cold water. Make sure the pieces are well drained before setting aside.
In a bowl, combine the self-raising flour and cornflour. Whisk in the ice cold water with 1 teaspoon of salt. Mix until left with a smooth, lump-free batter.
Heat the oil in the deep-fat fryer to 180˚C/350˚F/gas mark 5.
Add the plain flour to a bowl and use to dust the cauliflower and broccoli.
Coat each piece of vegetable in the batter before carefully placing in the deep fat fryer with a slotted spoon.
Allow the vegetables to fry for 2-3 minutes, until golden and crisp. Carefully remove from the fryer and leave to rest and drain on some kitchen towel.
Repeat the process until you have cooked all the cauliflower and broccoli.
To make the curry mayonnaise, mix the mayonnaise and the curry powder together in a bowl. Add the lemon juice and mix together well.
To serve, add the fritters to a large bowl alongside a dish of the curry mayonnaise.