Step 1
In a medium bowl, toss the beef with the soy sauce, bicarbonate of soda, 1 tsp ginger, 1 tsp cornflour, and ¼ tsp pepper. Set aside at room temperature for 30 mins to develop the flavours. In a small bowl, whisk the oyster sauce, sugar, sesame oil, extra soy sauce and remaining cornflour with 1/3 cup (80ml) water and 1/2 tsp pepper. Reserve the sauce mixture.
Step 2
Place noodles in a large heatproof bowl. Cover with boiling water. Set aside for 10-15 mins to soften. Drain well.
Step 3
Meanwhile, heat a large frying pan over high heat. Add 2 tsp vegetable oil and heat until just smoking. Add half the beef in a single layer. Cook, without stirring, for 1 min. Cook, stirring occasionally, for 1 min or until beef is browned. Transfer to a heatproof bowl. Wipe the pan clean and repeat with the remaining beef and 2 tsp vegetable oil.
Step 4
Wipe the pan clean and return to high heat. Add the remaining vegetable oil and heat until just smoking. Add the mushrooms in a single layer and cook, without stirring, for 1 min. Add the beans and cook, stirring frequently, for 3-4 mins, or until the beans are browned in spots and crisp-tender. Add the garlic and remaining ginger and cook, stirring frequently, for 30 secs. Add the noodles and cook, stirring constantly, for 1 min or until noodles are completely soft.
Step 5
Whisk the reserved sauce mixture to loosen and add to the noodle mixture in the pan. Return the beef to the pan. Cook, stirring constantly, until sauce thickens and coats the noodles.
Serve with spring onion curls