All fishmongers know what kind of fish is used for sushi.
It is very important to ask for fish for sushi. Fish for sushi has a completely different quality than fish to be fried.
The reason for the difference in quality of fish is that fish for sushi being eaten raw. It is very important to use top quality fish. If you eat raw fish that has become too old you may become ill.
At Sushi course for beginners I talk more about what kind of fish to buy for sushi
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Zoë has held sushi courses and cooking classes for A. P. Moller – Maersk, Hugo Boss Nordic, Novo Nordisk, Novartis, Velux, Gorrissen Federspiel, Beierholm revision, Elbek & Vejrup and many more.