You do not want your ingredients to burn in the wok. However, part of how you cook with a wok is to give your wok meal the so called 'breath of the wok' which comes partly from the searing of the ingredients in the wok cooking process. You DO want the ingredients to sear. If you cook your ingredients completely dry they may not cook rapidly or efficiently (remember we want our easy wok recipes to also be quick as well as easy) or they may burn before cooking thoroughly. A very little bit of water goes a long way in terms of speeding up the cooking process by creating super hot steam under the cover of the wok - and when used sparingly will not prevent searing from taking place!