I'd like to prepare dinner to be ready around 6 p.m. I have more time to prepare few courses and kids have better appetite. I am not really hungry either until then. When my wife is not home there is zero problem. I just tell kids to either help me or piss off. They comply. Wife does not.

I kid you not. She will act like a ninja sneaking into a fridge behind my back and start shoving some shit to the kids mouths. Either that or she will take whatever seems to be kind of ready and start the dinner with that behind my back when I don't see.

Reason behind is that she is hungry and cannot act like a grown up and wait 30 minutes to an hour.

Tried telling her on the spot to wait. Told her to eat a sandwich if she is going to die. Stopped her physically from messing my dinner -> she reverted to ninja tactics. Had a talk about it one evening and she agreed that it is a good idea to have dinner a bit later. Then she comes back around maybe a week later and uses kids as an excuse (because they are hungry).

If I have to get something from the store I simply can't trust her to keep the kids in line (not eat anything).

All input is very much appreciated. Been lurking here for about a month or so. Great sub.

EDIT:

Thanks for suggestions. I just need to get this thing under control and start enforcing a routine. I've been slipping too much and for too long on this to be honest. Not going to explain this to her, just need to adopt "Oh I can and I will".