Polynesians introduced the islands to the imu oven, used to make kalua pork. Traditional underground ovens were used throughout Polynesia and even the Americas to cook and steam food. Today, they’re used mostly for ceremonial and luau purposes. To construct an imu, Hawaiians dig about two to four feet into the soil and create a sloping pit to fill with kindling and stones. Once the kindling is lit and the rocks have heated, a process that usually takes a few hours, banana stalks and banana, or ti, leaves are placed over the rocks to create steam.

Before the cleaned and cut puaa (pig) is set in the oven, hot rocks from the slowly burning fire are placed inside it and the pig is covered with more leaves. It’s seasoned with sea salt, or sometimes red alaea salt, which has a deep history with ancient Hawaiian culture. That pinkish red salt, which gets its color from being mixed with volcanic clay found off the islands, has been used for centuries in purification and cleansing rituals.

The Hawaiian word kalua translates as "baked in an earth oven," which is how kalua pork gets its slow-roasted tenderness. The cleaned and seasoned pig is laid to cook over the hot rocks and covered with more banana leaves and a wet burlap to retain moisture. Once the pig is set to cook, the imu is covered back up with sand and soil. While the pig roasts in the imu, it absorbs the flavors of the wood and charcoal and the steam coming from the vegetation. It takes upwards of eight hours for kalua pork to cook. The results? Tender, juicy meat that practically falls off the bone.

Polynesians brought pigs to Hawaii when they settled the islands around 400 A.D. They also introduced taro (a plant that’s made into a starch called poi), yams, coconut, and sugarcane. Kalua pork is typically served with many of theses native dishes, and also with laulau (pork, chicken, or fish wrapped in taro leaves and steamed), poke (the Hawaiian version of sashimi), lomi salmon (cured salmon diced with tomatoes, onions, and chili peppers), and, of course, pineapple.

Pork is associated with many ancient Hawaiian rituals and religious sacrifice — and even represented by a demi-god: a half-man, half-pig called Kamapua‘a (or "pig child"). Hawaiians believed that eating pork and other foods that the gods had once eaten would bestow divine potency (or mana) upon them. But the only Hawaiians who ate pork regularly were the aili, or chiefs, who feasted on large amounts of it throughout the year. Commoners ate pork only during special occasions, and men and women had to eat separately. Only in 1819, under King Kamehameha II’s rule, were religious and food sacrifices banned, and women were allowed to join in the feast.