Food is hearty and fresh in Tonga, where folks still grow and raise much of what they consume, and food shopping takes place at roadside open markets and small grocers.

“It’s all whole foods, pretty much,” said Ana Fisilau, a native of Tonga who lives on Oahu. “Each family owns their own farm and lives off mostly what they grow.”

Fisilau is organizing a Tonga National Day celebration at Olomana Night Market on Monday that commemorates the formation of the country’s constitution.

Tonga’s lineup of traditional dishes well resembles classic food beloved by Hawaii eaters. There’s “lu,” meat wrapped in taro leaves and steamed; “ota,” bite-size pieces of seasoned raw fish; suckling pig (cooked on a spit); and an abundance of sweet potatoes (“kumala”) and taro (“talo”). Much of the cooking is still regularly done in “umu,” underground ovens heated with fiery hot rocks.

But there’s one big distinction: The Tongan versions of laulau, poke, sweet potato and kalo are all prepared with fresh coconut milk.

“It’s a staple in Tongan cooking,” said Fisilau. “It replaces broth in cooking here. There’s no beef or chicken broth. If we do use broth, it’s powdered. There’s not much canned goods in Tonga.”

Among menu items at the night market will be corned beef and lamb lu; sweet potato, taro and tapioca cooked in coconut milk; mussels, a favorite food in Tonga, baked with vegetables in coconut milk; ota, made in traditional fashion with diced fish marinated in lemon juice and tossed with green onions, tomato and coconut milk; corned beef sandwiches, with the corned beef prepared as a spread; “sakakai,” a dessert of boiled bread pieces covered in a sweet sauce of brown sugar and butter; and various “otai,” a drink resembling a smoothie comprising fruit chunks, half-and-half or Carnation evaporated milk, various sugars and water. 808 Burgers, owned by Fisilau’s cousin Olivia Moore, will prepare all the food.

As an island nation, Tongans consume lots of seafood such as lobster, octopus, seaweed, sea urchin, sea snail and, of course, fish. Common fish preparations include stuffing with vegetables and either baking or steaming in coconut milk.

Fisilau said that while people raise some livestock, it’s common for them to shop for frozen meat such as beef and lamb, though most raise and slaughter their own chickens.

Seasoning of all dishes is usually limited to lemon juice and salt since markets don’t offer much variety in seasonings and aren’t consistently stocked.

The high level of self-sufficiency in Tongan society extends beyond the food that is grown and raised. People have umu of different sizes on their land and use smaller ones to prepare everyday meals. Fisilau said that while everyone has a stove, umu are especially vital during hurricane season when the electrical supply can be tenuous.

“If the electricity goes out, we have no backup,” she said. “When it goes out, it goes out for a long time, days long.”

The upside: “Food tastes better from the umu.”