I was in KL for the day and met a friend for breakfast before a meeting. He suggested Ah Koong Fishball. They also have branches in JB, which I have been to.
This is more like a Yong Tau Foo restaurant than anything. You go to the front counter, choose what items you want and what noodles, and they’ll cook it and bring it to you.
They have a basic set – noodles with some fishballs and veggie. Then usually they add it into the same bowl, but sometimes they separate it out.
This is more than the basic, but then they also added more later.
Here are extra items.