The Fancy Beast chicken feast classic is the fave in out household for over 10 years.
I always leave a few bowls of the wet out for the 'kids' to eat and it's never hurt them for it to sit out for half a day. Also, I never go by the serving suggetions on the can, I put out what I think they'll need and my vet is A OK with that. (Cougars bury their food for weeks and will come back and eat from their cache.)
What I do to make the stiff pate' easier to eat is this. I empty the food into a bowl, mash it up a bit with a fork and then add 2 to 3 tablespoons of filtered water to the bowl and mash that up to a nice medium (but not soupy) 'slurry' as my vet tech/babysitter/housesitter calls it. She got me into doing this as she found that all the cats prefered a nice consistancy to the wet food, they eat it all up and there was no waste.
For Blondie, being that he had the 'dire beasties', this was the perfect food to have out for him and he thrived on his Fancy Beast being presented to him each day in this manner, for years.
This way of adding the filtered water to the Fancy Beast helps keep the furkids hydrated and there is no waste of food. just be sure you don't put too much water in it if you try it this way. V