This refers to the rapid cooling of vegetables after they have been blanched. They should be placed under running cold water immediately they are ready and left to get cold; they should then be well drained. Only vegetables which are going to be further cooked by braising should be refreshed after blanching, but if because of the exigencies of the service it is necessary to cook green vegetables in advance, they must be refreshed.
A vegetable which is to have butter or cream mixed into it will lose a lot of its flavour if refreshed.