I’m not sure what to tell you.
I’m almost certain you are not allowed to do that.
You are, however, allowed to put food which is already cooked and is dry on a ??? ?? ??? ???, a pot on top of a pot.
So, people will put something on top of a crockpot or on top of an overturned pot on the stove.
I guess you could tell your parents that you heard it may be an issue, and suggest they ask the rabbi again. It is easier if you already have other solutions, so present that also.
As far as you eating it, it is probably not a problem, since it was already cooked, but I can’t say for certain.