Yoshinori Ishii is an executive chef at Japanese restaurant Umu in London. If you are serious about making real sushi, learning from a professional chef makes a big difference. The takeaway from this video is the importance of selecting the freshest seafood. A sushi chef knows how to pick the best fish, an indispensable skill that every chef needs to master. The odd looking thing you see in the video is a real wasabi root. Fresh wasabi is not readily available. It is very expensive and you will not find it even at an Asian market. Fresh wasabi is used only at high-end Japanese restaurants. The green wasabi sold at a store is not pure wasabi. It is mixed with other types of horse radish and food coloring is added.