Reheating chicken in the microwave is usually a disaster, rubbery and awful or underheated. In the toaster oven, the meat will frequently dry out. How can I reheat it and keep the texture reasonable?
Try wrapping it in foil and cooking on a very low temperature in the oven or toaster oven. (Our oven has a "warm" setting that's ~170 F.) You can also include some water or broth in your foil packet but it won't penetrate much beyond the surface if the meat has been cooked before. It'll make that 1st bite taste more moist but in the long run it won't do much.
Usually, when I want to reuse chicken from yesterday, I cut it and put it in a quiche.
I microwave it on defrost mode or, say, at 20% of full strength. This also works for steak, pork, etc. It takes longer than "hard nuking" it, but the wait is worth it.
inject it with a syringe ( water , spices oil maybe) . reheat it
You can just pull out a pan and heat the stove really quickly then fry it without oil, it'll get crispy and not chewy. It's really good and it works within three minutes.