When your food cooked and still too hot to eat and also have at least 0.1% decay level you can use knife to remove decay level as well as reset heat level to 0 so you can instantly start consume cooked food without waiting

1.7.10 is no longer being maintained. FYI there is no too hot to eat it just does an odd animation; keep holding and it will be consumed. Even putting food alone in crafting grub will set heat to 0.