Bring water to a boil in a saucepan.
Add chopped green chilli, coriander leaves, ginger, red chilli flakes, and salt. Mix well.
Gradually add suji/rava while stirring continuously. Cook for 5 minutes, ensuring no lumps form.
Transfer the mixture to a bowl and drizzle with 1 tbsp of oil. Knead the dough well.
Apply oil to your palm and take a small portion of the dough. Roll and flatten it slightly.
Create a hole in the centre of each vada using a greased finger.
Heat oil in a wok over medium-high flame. Carefully drop the vadas into the hot oil, avoiding overcrowding.
Let them cook undisturbed for a few minutes, then stir. Cook until crispy and slightly golden brown.
Transfer the vadas to a bowl lined with absorbent paper.
Serve hot with tomato ketchup.