Already many centuries ago, Malaysia was on the spice route and still, many spices are part of the daily cooking. In Malaysian cooking, many different influences can be found, probably as many as populations that have visited the country for long term trading or invading.
One of the major likenesses is with the Indonesian kitchen; a soup like soto ayam may be found in both. A lot of recipes look Indian, others have a similarity to Chinese. Roti canai is very popular for breakfast and dinner, Roti canai could be Indian, it looks like a luxury version of chapati or the Bangladeshi paratha. It is eaten with sugar for breakfast or with dahl curry. For lunch, the meal is often served in a banana leaf, like in Bali. The Nonya cuisine (Nonya means woman in the Chinese Hokkien dialect but refers to Malay women of high social standing, married to strait-Chinese businessmen five centuries ago) is a combination of Malay and Chinese cuisine.
Stir frying in the wok is common and many spices are used, and they are processed using a pestle and mortar. Fish, cuttlefish and shrimps are part of many dishes. A popular dish is Laksa, noodles in spicy coconut soup, with prawn paste (belachan), shrimp, lemon grass and chicken. Even though laksa means thousand(s), which is supposed to be the number of ingredients of this soup, there is no need to worry, there are many ingredients to it, but not so many, and most of them are spices anyway.
After the 16th century, Portuguese, English and Dutch came to the island. Especially the British in the 19th century encouraged Chinese to work in the tin mines, leading to the further introduction and stabilization of availability Chinese dishes in the Malaysian kitchen.
Even inside Malaysia, differences are found. For instance in Sabah, Borneo, apart from the mentioned 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.