The process of immersing food in boiling water to lightly cook it or soften it is usually called blanching. A closely related technique is parboiling, which involves immersing food in boiling water for a specific length of time. The two terms are often used interchangeably. A number of the recipes here call for blanching pea tendrils or other greens before adding them to noodle soups, or parboiling or blanching greens before using them as an ingredient in a salad.