Our existing meal requirements are [ingredients not to be provided or other requirements]. For the proposed menu, please identify what can be substituted, what cannot and what still needs checking. Would you provide the replacement food, or would I need to bring it? If the menu or supply changes that day, who will contact me and when to confirm what happens next? Please state anything you cannot carry out. I am not requesting a dietary plan or treating the reply as a guarantee against cross-contact.
