Rinse the rice and tip it into a small pan. Pour in 350ml boiling water. Cover. Bring to the boil. Turn the heat right down. Simmer for 8 mins till all the water is absorbed. Take off the heat. Set aside, lid on, for 2-4 mins to finish cooking the rice.
While the rice cooks, mix together 2 tbsp brown rice vinegar and 1 tbsp sugar with half the sachet of tamari in a small bowl. Set aside.
Slice the pork into thin strips, about the size of your finger. Peel and slice the red onion. Halve the pepper. Scoop out the seeds and white bits. Slice the pepper into thin strips. Shred the Chinese leaf.
Heat ½ tbsp oil in a deep frying pan or wok. Add the pork. Stir fry for 4-5 mins till it begins to brown.
Add the onion and pepper to the pork. Stir fry for another 5 mins till the veg look soft and glossy.
Add the Chinese leaf to the pan. Stir fry for 1 min to just wilt it. Stir in the sugar and vinegar mix with 3 tbsp cold water. Bring to the boil. Heat through for 1 min.
Taste the stir-fry and add more tamari if you think it needs it. Serve with the rice in warm bowls.