Chilean Sea Bass with Choy Sum and Onion Relish

Chilean sea bass, also known as a Patagonian toothfish, is a white flaky fish in the cod family. It is a large, slow-growing, deep-swimming fish that mostly inhabits the southern Pacific and Antarctica. Not an inexpensive fish, but a real treat and now MSC-certified. Chilean sea bass is found in the fish counter at most good fishmongers.