Sift flour and 2 teaspoons salt into a large bowl. Add 1½ cups water and stir until smooth. Add all vegetables, garlic and pepper to taste. Stir to combine.
Heat oil in a frying pan or wok on medium-high until a cube of bread sizzles on contact. Cook 2 tablespoons of batter per fritter, in batches, for 2 minutes each side, until golden.
Drain on paper towel. Scatter with extra onion and serve with chilli sauce.
