Heat the oil in a wide pan over medium heat until hot but not smoking.

Add the finely chopped onion and cook for a few minutes, stirring regularly, until soft and lightly translucent.

Stir in the chopped garlic and sauté briefly until fragrant, taking care not to let it brown.

Add the cabbage, carrot, and bell pepper, then cook for several minutes, stirring often, until the vegetables soften and reduce slightly.

Mix in the cooked shredded chicken and stir well so it is evenly distributed with the vegetables.

Sprinkle in the salt, chilli flakes, black pepper, and soy sauce, then cook for a few more minutes until everything is well combined and flavourful. Remove from the heat and allow the filling to cool completely.

In a small bowl, mix the plain flour with enough water to form a smooth, lump-free paste that will be used for sealing.

Lay a spring roll sheet flat, place a portion of the filling near one edge, and roll tightly, folding in the sides as you go. Seal the edge with a little of the flour paste.

Repeat with the remaining sheets and filling. At this stage, the rolls can be frozen for later use if desired.

Heat oil in a deep pan over medium heat, then carefully add the spring rolls in batches.

Fry gently, turning halfway through, until evenly golden and crisp on all sides.

Remove and drain briefly, then serve hot with chutney.