Peel and grate or crush the garlic. Peel and grate the ginger. Mix them both in a bowl with the hoisin sauce. Add the beef stir-fry strips. Stir a few times to coat in the marinade. Put to one side.
Fill the kettle and boil it. Finely slice the mushrooms. Halve the Chinese leaf. Finely shred one half. Keep the other half for another day. Trim and finely slice the spring onions.
Fill a pan with hot water from the kettle. Add half the pack of noodles. Simmer over a medium heat for 3 mins. Drain well. Tip back in the pan. Cover with a little hot water to keep them warm.
Warm 1 tbsp olive oil in a deep frying pan or wok. Lift the beef out of its marinade (keep the marinade for later). Add it to the pan. Stir fry for 2-3 mins till the beef starts to pick up some colour.
Add the mushrooms and spring onions to the pan. Stir fry for 4-5 mins till the spring onions are glossy and the mushrooms are juicy.
Add 150ml hot water from the kettle to the marinade left in the bowl. Stir to mix it all together. Add it to the pan. Let it sizzle and simmer for 2-3 mins. Taste and add salt if it needs it.
Add the Chinese leaf to the pan. Stir fry for 2-3 mins to wilt it.
Drain the noodles. Toss them with ½ tbsp olive oil. Top the noodles with the beef and mushroom stir-fry. Serve straight away.