Begin by soaking the dried mushrooms in the boiling water for 10 minutes.
Whilst these are soaking, cut your spring onions and carrots into batons 2-3cm (¾-1¼") long and as thin as you can.
Finely slice your garlic cloves.
Peel the ginger and cut it into batons as thinly as you can.
Slice your beef across the grain into 2-3mm (⅛") thick slices 4-5cm (1¾-2") long.
Heat a wok over a fierce heat and then add half of the oil.Season the beef with salt and pepper, then stir fry until nicely coloured (2 minutes). Remove the beef and set it aside.
Return the wok to the heat, add the remaining oil and then stir-fry the garlic, ginger, carrots, and spring onions for 2 minutes.
Add in the rice wine, followed by the soy sauces and beef stock, then the dried mushrooms and the steeping liquid.
Bring this to a boil and then reduce to a simmer for 5 minutes.
Add the noodles and simmer for 2 minutes.
Add the beef and spinach, cook for a final 30-60 seconds and serve immediately.