Definitely a cockatrice.
If it looks like a rooster (i.e. a cock) it is a cockatrice... i.e. snek-chickens.
Basilisks vary more in appearance but they're almost always lizards in some form.
Also the cockatrice has decay / instant death breath, while the basilisk has petrification vision like a gorgon.
They're very different creatures, so it is weird the way they're mixed up.
... But then a lot of creators routinely mix up wyverns and dragons, which is just bizarre.
Plus griffons, griffins, hippogriffs, etc.
ALSO I'm just putting this out there, but chickens are not acceptable as food. They smell bad enough when alive, but the smell is worse than raw sewage when cooked. Now just imagine something that is mostly chicken AND a living instakill hazard with rot-breath. I can't imagine anything LESS edible than a cockatrice. Yet cockatrice-karaage keeps popping up in isekai series. So I'm inclined to say that if you attempt such a thing, you probably deserve the terrible fate that results.
Anyway... this chapter is making me feel ill. They might as well be eating an Otyugh.