Food you are allowed to board with

[flapsforty]

Bardos, as already said by others, sardines are a very bad idea and even if you remove all the liquid and get them through security in a tupperware box, the cabin crew might well take them away from you once the smell spreads through the cabin.

Getting caught nicking cutlery will put a premature end to your travels. Is a spoon worth that?
If you tell us what airline you will be flying, someone here will be able to tell you if they are willing and able to supply you with a cutlery set. All legacy carriers have them, no idea about Locos.
The spork mentioned by 419 is excellent; I have crossed worldwide security points with one of those in my flightbag for years.

Solid foods, preferably non smelly ones, will not be a problem. Most cabin crew will even be happy to keep them in the onboard fridge for you.

Many passengers with special needs come completely unprepared and expect cabin crew to magically produce whatever it is they need. And get shirty when we are unable to supply medicines/kosher/gluten free/ diabetic food out of thin air at 30 000 ft.
So compliments on your wish to be suitably prepared.