Prepare the Glass Noodles: Place the dried glass noodles in a heatproof bowl and cover with boiling water. Let them soak for 5-7 minutes, or until softened and pliable. Drain them thoroughly and, using kitchen scissors, snip them into shorter, more manageable lengths (about 5cm). Set aside.

Sauté the Aromatics and Vegetables: Heat 2 tablespoons of vegetable oil in a large wok or frying pan over a medium-high heat. Add the minced garlic and sliced shiitake mushrooms and stir-fry for 2-3 minutes until the mushrooms have softened and are lightly browned.

Cook the Filling: Add the julienned carrots and shredded cabbage to the wok. Continue to stir-fry for another 3-4 minutes until the vegetables have softened but still retain a slight bite. You don't want them to become mushy.

Combine and Season: Add the drained beansprouts and the chopped glass noodles to the wok. Pour in the soy sauce, sesame oil, white pepper, and sugar. Toss everything together for 1-2 minutes until well combined and the liquid has mostly evaporated.

Cool the Filling: This is a crucial step! Transfer the filling to a large, shallow dish and spread it out in an even layer. This helps it cool down quickly. Let it cool to room temperature for at least 20 minutes. Wrapping with warm filling will create steam and make the wrappers soggy.

Wrap the Spring Rolls: Mix the cornflour and cold water in a small bowl to create a slurry. Lay a spring roll wrapper on a clean, dry surface with one corner pointing towards you (like a diamond). Place about 2 heaped tablespoons of the cooled filling in a log shape near the bottom corner. Fold the bottom corner up and over the filling, tucking it in tightly. Fold in the left and right corners towards the centre, like an envelope. Then, roll it forward tightly towards the top corner. Brush a little cornflour slurry on the final corner to seal it shut. Repeat with the remaining wrappers and filling. I find that keeping the wrapped rolls covered with a damp cloth prevents them from drying out as I work.

Fry the Rolls: Heat 1 litre of vegetable oil in a deep pan or wok to 180°C (350°F). If you don't have a thermometer, a small piece of wrapper should sizzle immediately and turn golden in about 30 seconds. Carefully slide 3-4 rolls into the hot oil, ensuring not to overcrowd the pan. Fry for 3-5 minutes, turning occasionally, until they are a deep golden brown and beautifully crisp.

Drain and Serve: Remove the cooked spring rolls with a slotted spoon and let them drain on a wire rack. Draining on paper towels can trap steam and soften the crust. Serve hot with your favourite dipping sauce, like a sweet chilli sauce or a simple soy-vinegar dip.