Although Tears of the Kingdom does allow you to cook with some seriously questionable items, Critters, and Monster Parts are grayed out and off-limits. This is because these items form the basis for elixirs, another type of consumable that can boost status effects in a myriad of different ways, separate from foods. Other than these items, though, everything else is cookable, so mix and match in as weird a way as you want and see what hidden gems you can find!