Cook the beef filling: Heat 2 tablespoons of vegetable oil in a large frying pan over high heat until the oil shimmers and ripples. Add the beef mince, breaking it apart with a wooden spoon. Cook for 5-6 minutes, stirring occasionally, until the beef turns from pink to a deep brown and you hear a vigorous sizzle. The moisture should evaporate, leaving browned bits sticking to the pan — this is where the flavour lives.

Sweat the aromatics: Reduce the heat to medium and add the diced onion. Stir for 3 minutes until the onion becomes translucent and releases a sweet, fragrant smell. Add the garlic and ginger, stirring constantly for 30 seconds until the kitchen fills with their warm, pungent aroma.

Add the vegetables: Toss in the grated carrots, shredded cabbage, and bean sprouts. Stir-fry for 2-3 minutes until the cabbage wilts and turns a vibrant, brighter green. The vegetables should still have a slight crunch — they'll continue cooking inside the spring rolls.

Season the filling: Pour in the soy sauce, oyster sauce, sesame oil, white pepper, and salt. Stir thoroughly until everything is evenly coated and the mixture looks glossy. Cook for 1 more minute, then remove from heat. Transfer the filling to a wide, shallow bowl and spread it out to cool completely — this is crucial, as warm filling will steam the wrappers from the inside.

Prepare the wrappers: Lay one spring roll wrapper on a clean, dry surface with a corner pointing toward you (diamond position). Have your flour paste and a pastry brush ready. Place about 2 tablespoons of the cooled filling in a log shape across the bottom third of the wrapper, leaving a 3cm border at the bottom corner.

Roll the spring rolls: Fold the bottom corner tightly over the filling, then fold in the left and right corners toward the centre, pressing gently to seal. Roll upward firmly but not too tightly — you want the roll snug, but over-tightening can cause the wrapper to tear during frying. When you reach the top corner, brush the exposed edge with flour paste and roll to seal. The finished roll should feel firm and look like a neat, compact cylinder.

First fry (the foundation): Heat at least 5cm of vegetable oil in a deep, heavy-bottomed pan to 160°C (320°F). Fry the spring rolls in batches of 5-6, being careful not to overcrowd. Cook for 4-5 minutes, turning occasionally, until they're pale golden and the wrapper looks set and firm. The oil will bubble vigorously, and the rolls will feel light and rigid. Drain on paper towels and let them rest for 10 minutes — this step ensures the interior stays fluffy while the exterior dries out.

Second fry (the crunch): Increase the oil temperature to 190°C (375°F). Return the spring rolls to the oil in the same batches and fry for 2-3 minutes. Watch as they transform: the pale golden colour deepens to a rich amber brown, the surface becomes textured and bubbled, and the sizzling sound becomes sharper and more rapid. When they float to the surface and look beautifully bronzed, they're ready. Drain on fresh paper towels and sprinkle lightly with salt while still hot.