M.M.
We don't typically have sugar cereals or poptarts in the house on an option, that is Grandma's house. :)
Both my sons hit the picky place. I too followed with food for a bit when they were smaller.
I found a trick -- I made oatmeal raisen cookies or muffins and added a little bit of chopped pecans or walnuts and a banana. It had everything in it and I allowed as much as they wanted. It was a fix during a temporary patch of time.
Yogurt or fruit are always an available option in addition to the usual waffles, french toast, eggs/toast, multigrain cereals, oatmeal and farina.
Cold pizza has worked on a few days too! LOL Good nurishment is our goal -- not particular at what part of the day they choose to get the bulk of it.