Sprinkle two tablespoons of cornflour on the babycorn pieces and mix well. Sprinkle two tablespoons of water if you find it too dry. Heat sufficient oil in a wok and deep fry babycorn for three to four minutes or until crisp.
Drain on absorbent kitchen towel. Mix two tablespoons of cornflour in one cup of water.
Heat three tablespoons oil in a wok, add red chillies and garlic stir-fry for half a minute. Add tomato sauce, vinegar, red chilli paste, hot black bean paste, sugar and salt.
Stir in vegetable stock and continue to cook on high heat for a minute. Add both the capsicums, onion and spring onion and cook for a couple of minutes more.
Stir in cornflour mixture and cook till the sauce begins to thicken. Add deep fried babycorn and toss well to coat. Drizzle sesame oil, sprinkle red chilli flakes and serve hot.