Gok’s Chinese mussels with black bean sauce

2 tbsp groundnut oil

2 garlic cloves, peeled and finely sliced

2 sticks of celery, finely sliced at an angle

3 spring onions, finely sliced into rounds

1.5kg mussels, scrubbed and de-bearded

75ml Shaoxing rice wine or dry sherry

2 tbsp black beans, soaked in water for 10 minutes and drained

2 tbsp oyster sauce

1 tbsp dark soy sauce