When you say "Malaysian (cuisine)" do you really mean "Malaysian Cuisine" or do you mean "MALAY cuisine"?
When you say "Indonesian (cuisine)" do you mean pan-Indonesian Cuisine or any particular subset of it?
Keep in mind, as one example, that even Peranakan cuisine is both Malaysian and Indonesian because it exists in both countries.
If you mean MALAY cuisine vs the dominant generalized kind of cuisine found in Indonesia then many of the regionalities are subsets of a broad spectrum, yes - with dishes that are common to both Malay cuisine and Javanese or Sumatran cuisine &etc, say (rendang being one example - with Minangkabau origins), but perhaps with different spicing and/or way of preparation. "Nasi Goreng" (literally, "fried rice") is another dish that is ubiquitous in both countries overlapping both Malay (and even Malaysian-Chinese and Malaysian-Indian and Mamak & etc, to a point) cuisines as well as Sumatran/Javanese/Padang/etcetc cuisines but is frequently thought of in the West as "Indonesian". Here's an old thread here on eG on nasi goreng. There are also various food items in Java, especially, which look like clunky versions of "siu mai" or "wonton" but are called by Malay/Indonesian(as a language) names --- but that's because they ARE the local Chinese (Hakka, mainly) versions of same. "Fried chicken" can be done in various ways and will differ accouding to which ethnic or regional group is doing it, across Malaysia and Indonesia. Balinese cuisine (as a subset of Indonesian) has strong Hindu influences and includes a popular Balinese rendition of roast PIG which, of course, would be verboten in most of otherwise majority Muslim Indonesia. And so on.
(Take a long look at the many threads on eating in Indonesia (vs eating in Malaysia) especially those posted by a certain once-poster on another forum for lots of details on a personal level)
What was this restaurant you went to, and what was on their menu? Who were the owners? (ethnic Malay, or ethnic Chinese, or some other?)
