When it comes to Island foodways, says writer Arnold Hiura, what we don't know — and likely will never learn — is as intriguing as the few things we can document.

Who invented the plate lunch? When? Where? Why mac salad? Is shave ice a Japanese thing? Chicken long rice a Chinese thing?

In his new book, "Kau Kau: Cuisine and Culture in the Hawaiian Islands" (Watermark Publishing, large-format, $32.95) Hiura uncovers some intriguing bits that lend credence to various theories on these and other questions. But when his publisher George Ingebretsen urged him to make the book "definitive," his answer was, "Don't say that."

There's no such thing as definitive with Island food history. "Almost every iconic dish on the local table is impossible to nail down," he said.

No matter. The talk story, the reminiscing, the research and the speculation are as pleasurable to him as his Filipino neighbor's dinaguaan or his oba-chan's burnt rice onigiri (rice cakes).

Though it contains some 70 recipes, "Kau Kau" is less a cookbook than a memory book, transporting the reader (or even the casual page-turner, given the number of vintage photos and illustrations) as far back as pre-contact days. Old-timers will love the impressive collection of menu covers from such now-gone favorites as the Hob Nob (in the Alexander Young Hotel) and Kau Kau Korner, from Ingebretsen's private collection.

Hiura, 58, grew up in Päpa'aikou, then very much a sugar-cane plantation town on the Hämäkua Coast of the Big Island. A baby boomer, he feels sandwiched between his grandparents' generation and those of his children and grandchildren. He vividly recalls the everyday lives of the nisei and sansei (first and second generation) who raised him and were his neighbors. "Sometimes I feel older than I am," said Hiura, who lives on O'ahu now and is a self-employed writer, editor and consultant.

A journalist by trade (he is former editor of the Hawai'i Herald), his interest, he said, has always been in history and culture; he has worked as a curator for the Japanese American National Museum. Food is a rich avenue by which to get at deeper aspects of culture and history, he said.

"Food is something we celebrate and we enjoy, but it makes it better when you look at where it came from, what we had and didn't have," he said.

Hiura has tremendous respect for the simplicity and humility of Island immigrants and their immediate descendants, as reflected in what they ate and how it was prepared. They made do, adapting ingredients when they couldn't find the things of their homeland. They never wasted.

Remember that burnt rice? In the nostalgic closing essay of the book, Hiura pays homage to his grandmother who, in the days when rice was cooked over an open flame, always rescued the smoky browned rice kernels from the bottom of the pot, mixing them with a little salt. "She made it look delicious," he said.

In these relatively affluent, we-want-what-we-want-now days, he said, this spirit is all but lost, but worth reconsidering.

At the heart of Hiura's book are delightful talk-story sessions with salt-pan tenders in Hanapepe, restaurateurs such as the proprietors of Hilo's Cafe 100, food producers such as the folks who make Kitch'n Cook'd potato chips, ranchers such as Monty and Phyllis Richards of the Big Island's Kahua Ranch, food purveyors like those who operate Pukalani Superette in Makawao, chefs such as Alan Wong, and restaurateurs like the Higas, who own Zippy's.

One hilarious segment is "How Poor Were You?," a riff on an old schtick by Johnny Carson. He asked a bunch of folks how poor they were and the responses came. "We were so poor that " and there followed a litany of odd things that people ate. When it came to the guy who claimed his mother made grass stew, Hiura was laughing so hard he had tears in his eyes. But, he said, it might be a plausible story; some things we might call grass today are edible, and there was a lot more foraging in those days.

Hiura said he began with one viewpoint — one of loss and nostalgia — but ended with another.

"The biggest revelation was trying to connect the past with the present. At the onset, I felt more of a disconnect. I mean, although regional cuisine is very nice and very interesting, it's a world away (from the foods of his grandparents' and parents' day and, indeed, his own childhood)," he said. But in the process of doing the book, and talking to people like Alan Wong and farmers and ranchers, "I began to think there is a continuity. There is an important connection."

Take a dish like furikake salmon with wasabi mayonnaise or wasabi beurre blanc. "These chefs created and extended these things, but now you find them as specials in a drive in, or at a family potluck," Hiura said. "They have become part of the local palate."

At the heart of local food, he said, is sharing and blending. Take Spam musubi, he said: "It was not one particular ethnic tradition that it came from; it was shared. For me, the coming together part is what's important and what makes Hawai'i Hawai'i."