Inside Malaysia, differences in cooking are found. For instance in Sabah, Borneo, apart from Chinese and Indian inhabitants, there are more than 30 indigenous ethnic groups, which all have their own specific dishes. The largest group Kadazan Dusun, lives in mountains and valley and is busy on rice paddies, and rice is the main staple food. In other parts of the island, this may be corn or cassava. The Kadazan Dusun also use many seeds and roots, and river fish, and little oil, as that was not always available in the hard to reach interior of the island, so many recipes are cooked or simmered.
The second largest group, the Bajau, are originally a sea faring crowd and thus will have mostly fish on the menu. As the island of Borneo is covered with a huge rain forest, the menu is based on available ingredients, and you will find coconut juice, lime juice and banana leaves in many of the recipes. The latter two ingredients also help to increase shelf life of the food, as in the old days a fridge was not available, and in remote areas still is not. Therefore, also dried small fish (ikan bilis) and shrimp paste are very popular ingredients. As not all ingredients are always readily available everywhere, like for instance indigenous vegetables like sayur manis, and fruits like jackfruit, I sometimes adapted the recipes a little. Durians I have left out as well, even though they are very popular in Sabah, not only for their non availability, but also because most "Western" people hate the smell of this fruit.