i dont think you are actually asking permission to place a food order, more just informing of your intention - its a curious quirk the way people phrase things - things such as going in to a shop and asking -
" you don't have a 'whatever', do you?" - why not just ask for what you want, simply with a "do you have...", instead of starting by telling the shop assistant that they don't have it!
or people who ask a question that pointlessly starts with "is it just me or does..." - well obviously its not just you, so why say it?
i wonder if people feel subconsciously that it is more polite? or to sort of soften the blow of disappointment with a statement that, if the answer is negative, can be responded to with "oh, didn't think so" or "ahh, thought not"...?, as though they knew all along.
i mean is it just me or is this really irritating?
you don't agree with me, do you?