Local food is one of the enjoyment of the trip, yet it is very difficult to find local food in Papua New Guinea.
Most of the Hotels are serving only Western cousin, and there is no restaurant offering local food. - simply because people can cook local food in their home and nobody wants to eat outside !
This does not mean PNG has no local food.
There are different ways of cooking and different ingredients.
In Highlands, people use heated-stone to cook the food in an earth oven (in the ground), commonly known as Mumu.
The main protein can be Pork or Chicken, and cooked with Banana, Sweet Potato, Taro, Corn etc...
In Coastal area, some use Clay Pot to cook the Fish and vegetables. It is common to use Coconut Milk to give sweet taste in Coastal & Island area.
What is common in all the local dish is that there is no artificial ingredients, all chemical-free fresh food grown in the rich soil of PNG. Being a tourist, only way to eat those Yummy local food is to join the village tour, but make sure to ask if they offer local food.