Hi Sidneycat and welcome!
Yes, he is a handsome boy all right.
The behaviour you describe is normal and cats in the wild do this often. Sometimes they do it if they want to save some food for later. Like a squirrel does.
Sometimes though, your guess would be correct and Sidney might be telling you the food you are giving him is
and he'd prefer a change of menu.
No way really of telling which it is until you've learned more about Sidney's little foibles, although thinking about it his recent past as a stray may be making him feel a bit protective of his food. You'll know which scenario it is in the fullness of time. Looks like Sidney's training of you is a work in progress.