Pour the vinegar into the bowl. Add half the tamari (keep the rest for later). Stir in 2 tsp China 5 spice. Add the pork stir-fry strips. Turn to coat in the marinade. Set aside.
Prepare the veg for your stir-fry. Halve the pepper, scoop out the seeds and white bits, then slice it into long, thin lengths. Trim and peel the carrot. Slice it into thin batons. Thinly slice the pak choi leaves the thick stems. Keep the leaves and stems separate.
Trim the roots off the spring onion. Finely slice the white and green parts. Keep the green parts separate. Peel and grate the garlic and ginger. Put a large pan of salted water on to boil.
Warm a deep frying pan or wok for 2 mins. Add ½ tbsp oil. Lift the pork out of the marinade (keep the marinade for later) and add it to the pan. Stir fry for 3-5 mins till browned all over. Scoop out onto a plate.
Add another ½ tbsp oil to the pan. Add the white parts of the spring onion, the pak choi stems, the garlic and ginger. Stir fry for 30 secs. Pour in the marinade from the dish and let it sizzle.
Add the pepper and carrot to the pan. Stir fry for 5 mins till the veg have softened a little. Add the pork back to the pan with the pak choi leaves. Pour in 150ml boiling water and simmer for 2-3 mins to just cook everything through.
The water should be boiling in the pan by now. Add the rice noodles. Simmer for 3 mins till soft. Drain well and divide between two bowls. Taste the stir-fry and add more tamari if you think it needs it. Spoon over the noodles and serve garnished with the green spring onion tops.