Found it.... under In-flight services... 

but still not mention any price 

Only found this:
Pre-book meals
Looking for a deal? Pre-book online to save up to 15% on meals and avoid the disappointment of not getting the meals you want onboard.

What if I bought any food inside the terminal (before boarding)... can bring or not inside? My trip will reach the destination quite late, I afraid cannot find any halal food that time. My 1st time using AA for oversea flight.

1 hour on Skybus + 4 hours flight + appr 2 hours inside the terminal (departure + arrival) + 1 hour plus on bus to hotel, roughly 8 hours already. Definitely I will reach hotel around 11pm.

This is my 1st trip with family, so I going to make sure all are happy. If alone like before, don't care much. Some more my kids kuat makan... 
Thanks... I will order asap then. I only skip meal and insurance during the check-out.