The only time I offer an alternative (usually leftovers or cereal and fruit) is when we are having something "new" or someone REALLY REALLY honestly doesn't like. The only kid immune from this rule is the one who has food allergies and sensory integration dysfunction. (FS said that was bull so I offered to make him an appointment for allergy testing explaining the process and he changed his tune!) Thats one approach. The other is what my Mom did to me when I was about 12 and insisted Nachos were the only thing I could eat. She gave them to me 3 times a day everyday, and that was all I got (of course this may not work with a foster child when we are required to provide balanced meals but you get the idea). It took two days to cure me of my nacho phase and I still don't eat them.
Jen