Rinse the baby corn, trim the ends and cut any large baby corn in half lengthwise so pieces are uniform. Pat dry with kitchen paper. Dust lightly with 2 tablespoons of all-purpose flour to help the batter adhere; shake off excess.

Make the batter

In a mixing bowl combine 1 cup all-purpose flour, 1 cup cornstarch, 1 teaspoon baking powder, 1 teaspoon salt and 1 teaspoon freshly ground black pepper. Add 3 tablespoons cold water and whisk to make a relatively thick, smooth batter that coats the back of a spoon. If batter is too thick add water 1 teaspoon at a time; too thin and it won't cling.

Coat and fry

Heat 700 ml vegetable oil in a deep pan or wok to 180°C (350°F) — test with a small drop of batter; it should sizzle and rise. Dust baby corn lightly with the reserved 2 tablespoons flour, then dip each piece into the batter to coat evenly, letting excess drip off. Fry in batches (do not overcrowd) until golden and crisp, about 3–4 minutes per batch. Remove with a slotted spoon to a rack or paper towel-lined plate to drain. Keep warm.

Manchurian sauce & stir-fry

Prepare sauce base

In a small bowl whisk 1 teaspoon cornstarch with 2 tablespoons of the 125 ml water to make a smooth slurry; set aside. In the same 125 ml water, reserve the remainder for the sauce (about 115 ml).

Stir-fry aromatics and vegetables

Wipe the wok and heat 2 tablespoons vegetable oil over medium-high heat until shimmering. Add 1 tablespoon minced garlic, 1 tablespoon minced ginger and the 2 green chilies. Stir-fry for 20–30 seconds until fragrant but not browned. Add the white portion of the sliced spring onions, the sliced onion and the capsicum pieces. Stir-fry on high for 1.5–2 minutes so vegetables remain crisp-tender.

Build the sauce

Lower heat to medium. Add 3 tablespoons tomato ketchup, 1.5 tablespoons light soy sauce, 1 teaspoon dark soy sauce (optional), 1 tablespoon chili sauce, 1 teaspoon vinegar and 1 teaspoon sugar. Stir to combine and let it bubble for 20–30 seconds. Pour in the reserved ~115 ml water and bring to a simmer.

Thicken and season

Give the cornstarch slurry a quick stir and slowly pour it into the simmering sauce while stirring continuously. The sauce will thicken in 30–60 seconds to a glossy consistency that coats the back of a spoon. Taste and adjust seasoning with 1/2 teaspoon salt and 1/2 teaspoon freshly ground black pepper if needed.

Combine with fried baby corn

Raise heat to medium-high. Add the fried baby corn to the wok and toss gently to coat all pieces in the sauce, about 1 minute. Add the green spring onion tops and toss once. Cook just long enough for the baby corn to heat through and for the sauce to cling — avoid overcooking to keep the coating crisp.

Garnish & serve

Transfer the Baby Corn Manchuria to a serving plate. Sprinkle 2 tablespoons sliced spring onion greens and 1 teaspoon sesame seeds over the top. Serve immediately with lime wedges on the side to add brightness if desired. Best served hot as an appetizer or as part of a meal with fried rice or noodles.