Wash the mussels thoroughly, sort and drain them. Peel and slice the onions. Wash lemon grass, remove outer leaves if necessary. Cut the lemon grass into 2 pieces and beat them slightly with the back of a knife.
Clean, wash and cut the peppers into rings. Peel ginger and cut into strips. Clean, wash and cut the chilli pepper and remove the seeds. Cut the pod into pieces. Clean, wash and cut spring onions diagonally into rings.
Wash the basil and dab dry. Set something aside for garnishing. Pluck the basil leaves from the stems. Heat the oil in a large pot. Fry 1/3 spring onions, onions, chilli and lemongrass for 1-2 minutes.
Meanwhile, cook the rice in boiling salted water according to the instructions on the packet. Add the curry paste to the onions and continue frying for 1-2 minutes. Clean and thoroughly wash Pak Choi. Add broth, coconut milk and Pak Choi to the pot and bring to the boil.
Place the mussels, remaining spring onions and basil in the pot, cover and cook over a low heat for 4-5 minutes until the mussel shells are open. Stir occasionally. Discard unopened mussels.
Coarsely chop the macadamia nuts and roast them in a pan without fat until golden brown. Season curry with salt, lime juice and oyster sauce. Drain rice. Arrange curry and rice, sprinkle with macadamia nuts and garnish with basil.