1.Heat oil in a large saucepan over a medium heat; cook pork until browned all over. Add shallots, ginger and garlic to pan; cook for 1 minute.
2.Add sauce, sugar, star anise, stock and the water; bring to the boil. Reduce heat; simmer, covered, for 1 1/2 hours, turning pork occasionally.
3.Meanwhile, soak mushrooms in warm water for 20 minutes. Remove stems, cut in half. Add mushrooms and bamboo shoots to pan; simmer gently, uncovered, for further 30 minutes, turning pork occasionally.
4.Remove pork from pan; cover to keep warm. Strain cooking liquid into a large jug; reserve 2 1/2 cups (625ml). Reserve mushroom mixture.
5.Bring reserved cooking liquid to the boil in a medium saucepan; boil, uncovered, for 10 minutes or until reduced by half.
6.Meanwhile, place noodles in a heatproof bowl; cover with boiling water. Stand until tender; drain.
7.Boil, steam or microwave gai lan until just tender. Slice pork thickly.
8.Place noodles on serving plates; top with gai lan, pork and reserved mushroom mixture. Drizzle with sauce, top with green onion.
Yellow rock sugar is available from Asian supermarkets. It’s mainly used in braises and sauces as it gives them a lustre and glaze. To freeze; pour stock into freezer-proof containers, leaving a 2.5cm space to allow for expansion. Seal, label and freeze for up to 3 months. Thaw overnight in the fridge. Reheat in a saucepan or microwave on medium power (50%) until heated through.