Kālua is a traditional Hawaiian cooking method that utilizes an imu, or underground oven. The word kālua literally means "to cook in an underground oven" and also describes the flavor of food cooked in this manner - e.g. the kālua pig (Hawaiian puaʻa kālua) which is commonly served at luau feasts.Traditionally, extremely hot rocks were placed in a hole approximately 6' by 4' by 3' and the hole was lined with vegetation such as banana leaves. A salted pig was placed inside and covered with more banana leaves to preserve the heat and flavor. Then, it was covered with burlap and soil, and left to steam all day. Once removed from the imu, the pig was ready to be served.Modern-day technology has replaced the use of rocks and leaves, but kālua pig slow-cooked in an imu pit continues to be a main attraction at most luaus. United States Department of Agriculture standards prevent traditional kalua pig from being sold commercially. Some companies have attempted to imitate the kālua taste and even devised the imu pao (an above-ground variant of the imu), but most have failed to capture the distinct taste of a kālua pig.The term kālua pork is frequently used to describe any pork shoulder butt which is rubbed with salt, wrapped in ti plant leaves, and slow smoked, without regard for an imu. See alsopit ovenPachamancaHangi