The process of briefly immersing bok choy in boiling water, followed by immediate transfer to ice water, is a cooking technique employed to partially cook the vegetable. This method preserves the crisp texture and vibrant color while slightly softening the leaves. For instance, one might submerge cut bok choy stems and leaves in boiling water for approximately two minutes before transferring them to an ice bath to halt the cooking process.
This pretreatment offers several advantages. It reduces bitterness, diminishes strong odors, and facilitates even cooking in subsequent preparations like stir-fries or steaming. Historically, such methods have been used to prepare vegetables for preservation or to enhance their palatability. Furthermore, it can deactivate enzymes that cause discoloration or loss of nutrients, thereby extending shelf life.