Chef Stephen Gibbs shows you a good cooking technique: blanching and shocking vegetables. Blanching is letting vegetables in hot, boiling water for a short period of time. Shocking is putting hot vegetables in ice cold water. These methods are used together in order to precook certain vegetables or even take the skin off.
The chef demonstrates with tomatoes and beans. He cuts an X at the bottom of the tomato and keeps it for about 10 seconds in a pot with boiling water. He then moves it quickly to a pot with cold water. The skin then comes off nicely. The green beans are blanched and shocked in exactly the same way. They end up being three-quarters cooked and have a nice color.