Mix all the vegetables in a bowl and squeeze out all the water.
Add chopped garlic, ginger, salt, pepper and soya sauce.
Add all-purpose flour, corn starch and mix well.
Make small balls from the mixture and fry them in hot oil on medium flame till golden brown.
Remove the balls from the oil and place them on kitchen towel to drain the excess oil.
Now for the gravy, heat 2 Tbsp oil in a pan. Add finely chopped garlic, ginger, green chillies, onion, spring onion and fry them till golden brown.
Add soya sauce, vinegar, green chilli sauce, pepper powder and salt.
Add corn flour to thicken the gravy.
Add the Manchurian balls and toss gently to coat them with the sauces.
Transfer to a serving bowl and garnish with chopped spring onion. Serve hot.