HungryGoWhere published a slideshow of ten places where halal Chinese hawker food is available in Singapore in November 2013. In majority-Chinese Singapore, halal Chinese food is rare, and Chinese hawker food even rarer.
The list includes soup noodles (ban mian), steamed buns (kong bak pau), dimsum, Hokkien noodles, prawn noodles, flat rice noodles Ipoh style (Ipoh hor fun), Nyonya dumplings (bak chang), fried carrot cake, oyster omelette, and fried flat rice noodles (char kuay teow).
As things can change quickly, check the expiry date on the halal certification, which should be prominently displayed.