Take a large mixing bowl and add 1 cup finely chopped cabbage and ½ cup chopped spring onions, then mix well and squeeze out the excess water using your hands or a clean cloth so the mixture isn’t too wet.
Once the water is removed, add ½ cup grated carrots and ½ cup finely chopped capsicum into the same bowl, mixing everything thoroughly so the vegetables blend evenly.
Into this mixture, add 2 tablespoons cornflour, 2 tablespoons all-purpose flour, ½ teaspoon black pepper, ½ teaspoon salt, and 2 finely chopped green chilies, then combine well so the spices and flours coat the vegetables.
Keep mixing until you achieve a dough-like consistency that holds its shape; if the mixture feels too soft or sticky, sprinkle in a little extra flour to help bind it properly.
Take small portions of the dough and roll them into smooth, round balls with your hands, making sure they are firm and even in size for frying.
Heat oil in a deep frying pan over medium flame, and when the oil is hot, gently slide in the Manchurian balls in small batches without overcrowding the pan.
Fry the balls until they turn golden brown and crispy on all sides, then remove them with a slotted spoon and drain the excess oil on paper towels.
To make the gravy, heat 2 tablespoons oil in a pan, add 1 teaspoon finely chopped garlic and 1 teaspoon chopped ginger, and sauté for 1–2 minutes until fragrant.
Stir in 2 chopped green chilies, ½ cup chopped onions, ½ cup chopped bell pepper, and ½ cup chopped tomatoes, cooking for a minute before adding 1 teaspoon red chili powder or 1 tablespoon red chili sauce. In a separate bowl, mix 1 tablespoon cornflour with ¼ cup water to make a smooth slurry, then pour it into the pan while stirring.
Add 1 cup water, let the gravy simmer until it thickens, and season with ½ teaspoon black pepper and salt to taste.
Finally, add the fried Manchurian balls into the simmering gravy and cook for 5–10 minutes so they absorb the flavors. Turn off the heat, garnish with 2 tablespoons chopped spring onions, and serve hot Veg Manchurian with fried rice or noodles.