My husband is native to New Caledonia and we have visited on Ile-des-Pins-- I find it odd that the author of the tip was warned not to try the traditional dishes. Definitely find a place to have some Bougna! This is a traditional dish that is cooked in a pit in the ground, heated by fiery hot rocks... the bougna is wrapped in papaya leaves to be cooked and is a mix of seafood (or sometimes chicken) and various root vegetables like taro + a cookable variety of banana. If you don't try this, you never went to New Caledonia! There are also good coconut crab and giant escargot (which can be found crawling around among the wild impatiens of the loamy forest floors on the island!) to be had if you can find a gite (local "inn").
Restaurants will be hard to find and very expensive. I wondered into a beach side resort and paid $15 for a bowl of hot chips!! The staff were not too friendly either and I was more tolerated than anything. However I was pleasantly surprised when a group of local native women gathered on the esplanade of Kuto Bay with numerous traditional dishes. We had been warned on the ship to avoid eating this food but many tourists were tucking in. I refrained from the hot dishes [ chicken and vegetable affairs] but they smelt lovely! I did buy a piece of red paw paw for $2 and it was very nice.