Blanch

blanch means for the gardener to earth up vegetables such as (celery, leeks, or cardoons, etc.) and thus keep white.

The blanching carried out in the kitchen is often to parboil. A restaurant chef blanches green vegetables (refreshing them in cold water to arrest any further cooking) if he wishes to have them ready for later orders or for finishing in butter. And vegetables or herbs are blanched before they are frozen, deactivating enzymes and setting their colour.