Heat 2 tbs vegetable oil in a large skillet or wok over medium-high heat. Add the diced chicken in a single layer and cook, stirring occasionally, until cooked through and just starting to brown, about 5–6 minutes. Remove chicken to a bowl and set aside.

Cook vegetables

In the same skillet add a little more oil if needed, reduce heat to medium-high. Add minced garlic and ginger and stir-fry 20–30 seconds until fragrant. Add sliced mushrooms and shredded carrot and stir-fry 2–3 minutes until they begin to soften. Add shredded cabbage and sliced spring onions and stir-fry a further 2 minutes until cabbage wilts but still has some crunch.

Combine filling

Return cooked chicken to the skillet with the vegetables. Stir in light soy sauce (2 tbs), oyster sauce (1 tbs), sesame oil (1 tsp), cornstarch (1 tsp dissolved in 1 tbs water if preferred) and salt and pepper. Stir and cook 1 minute more so the sauce coats everything and thickens slightly. Remove from heat and stir through chopped coriander. Taste and adjust seasoning. Let the filling cool to warm (not hot) before wrapping — about 10 minutes; this prevents soggy wrappers and burns when handling.

Wrapping & sealing

Make sealing paste

Whisk together 2 tbs flour and 2 tbs water in a small bowl to form a paste (should be brushable; add a few drops more water if necessary).

Assemble rolls

Lay one spring roll wrapper flat on a clean surface with a corner pointing toward you (diamond shape) if square. Place about 2 tbs of cooled filling near the corner closest to you, forming a small log about 1–1.5 inches wide. Fold the corner over the filling, tuck the filling in while rolling once toward the center, fold in the two side corners snugly, then continue rolling to the far corner. Brush a little flour paste on the final corner to seal. Repeat with remaining wrappers and filling. You should have about 18–20 rolls depending on filling portioning.

Frying

Heat oil

Pour oil into a deep heavy saucepan or deep fryer so it is about 5 cm (2 inches) deep. Heat to 175–180°C (350–360°F). If you don't have a thermometer, test with the handle of a wooden spoon — small bubbles should form steadily around it.

Fry spring rolls

Work in batches to avoid overcrowding. Fry 4–6 rolls at a time for 3–4 minutes, turning occasionally, until golden brown and crisp on all sides. Use a slotted spoon to transfer rolls to a wire rack or paper towel-lined tray to drain. Let oil return to temperature between batches.

Finish

If the rolls are browning too quickly before heating through, reduce the heat slightly. Once all rolls are fried, rest them 2–3 minutes to set the crisp exterior.

To serve

Arrange spring rolls on a platter with sweet chilli sauce in a small bowl for dipping and lime wedges on the side. Serve hot and crispy.