The hot food in the arrivals lounge is cleared away at 12. They close like clockwork at 1400, too.
Given the fact you'll arrive at around 1130, and you'll need to clear immigration and customs, it's probably going to be well past 12 by the time you've got to the arrivals lounge and had a shower. Presumably you'll want to shower before you scoff breakfast?
I'd forego the arrivals lounge and just go straight to T5 galleries and get a showered and fed there. The curry isn't all that bad, really!