One of my cats only likes dried food so that is fine, the flies don't seem interested in that.
The fussy old cat gets a mixture of pouches & dried food, so I just give him as much of the pouch as I think he'll eat at one sitting then a bit more if he's still hungry. Then I leave out some dried food for him to graze on.
The dogs are more than happy to wolf down any leftovers. I think they like it better than dog food!
I feed mine dry so avoid this problem but in the heat I have been serving up a sachet in the evening either with crushed ice or extra water in it, or cat milk. it also gets demolished. Applaws definitely has this effect.