Heat oil in the fryer.
Combine cornflour, flour, bicarbonate of soda and sesame seeds in a large bowl and mix together.
Add water and whisk until a smooth batter is formed.
Add cauliflower to batter.
Allow excess batter to drip off.
Lower into the hot oil.
Repeat with remaining cauliflower until fryer is full.
Cook until evenly golden brown.
Transfer to a paper towel-lined plate.
Toss fried cauliflower with sauce and sprinkle with extra sesame seeds and chopped spring onions.