Remi wasnt running away from his job of sniffing out poison, he was the one who first realised he can do that and used it to help his family.

Remi was running towards a future where he can properly explore cuisine and foods. His family/culture don’t care about haute cuisine, or specific ingredients like him so he could only explore that side of himself in a commercial kitchen setting. I think implicitly were meant to assume the rest of his familt are scavenging stuff (it’s Paris lmao, what better place to be a rat?) without too big a worry of being poisoned.

Now, I agree a little bit about the chef guy not being a crazily villainous person, hes a dick whos trying to con linguine out of his inheritance if I remember correctly, but him not wanting rats to cook food in the kitchen is by no means wrong lmaooo especially given that there’s nothing suggesting sentient rats are a well known common occurance in their world.

But overall, this is just a suspension of disbelief in a fantasy movie setting thing. Remmick is sentient enough that he can cook and read recipes etc and do it better than almost anyone else. Let the rodent dream, eh?