A small piece of a square inch shouldn't hurt but birds should really not be given anything fried as they have trouble digesting animal fats.
If you want to give it treats it may be a better idea to give him a small piece of carrot, any green vege (the stalky bit), a 1/4 piece of raw corncob, a brussel sprout.
Only raw vegies, never cooked/boiled.
Pet parrots also do very well on pelleted diets but the bird may take some time to get used to them and if fed pellets solely it can lead to boredom problems such as plucking, so plenty of playing and distraction toys.
Stay away from those scientific sounding 'health' aid such as pro-biotics, anti-bacterial and so called essential vitamins, unless recommended by a vet. If your bird is sensibly fed it doesn't need them and may do more harm than good.
Try to think as a parrot, not as a human.