Blanch the pak choi in boiling salted water for 2-3 minutes.
Drain and squeeze out any excess water from the pak choi.
Melt 15g of butter in a frying pan and sauté the pak choi for a few minutes.
Arrange the pak choi on a warm plate.
Lightly dust the sea bass fillet with curry powder.
Heat the remaining 15g of butter and fry the fish skin-side down for 3-4 minutes.
Turn the fish and fry for one more minute until cooked through.
Place the fish on top of the pak choi.
Blend sesame oil, sesame seeds, chilli, and soy sauce in a mini food processor.
Spoon the chilli dressing around the pak choi and fish.
Toss the onion, oil, and parsley together in a bowl.
Serve the onion salad alongside the sea bass.