When I try to make chicken cheesesteaks, this is what I do:  thinly slice some chicken breasts saute some chopped onions and green peppers put the meat in a frying pan with some olive oil add some salt, pepper, and dried Italian herbs chop the meat some more and cook it thoroughly add in the chopped onions and green peppers put slices of cheese on top of the meat/veggies and allow it to melt  The meat always turns out dry. Then I read that chicken thighs are juicier and don't dry out like chicken breasts do (especially if you cook them longer and at a higher temperature, up to 195 degrees), so I tried doing the same thing except with thinly sliced chicken thighs. I monitored the temperature with an infrared thermometer and the temperature didn't get higher than 195 degrees. The meat still ended up tasting kind of dry. Also, a lot of liquid came out of the meat during cooking, before I added the veggies. How do I make a chicken cheesesteak that isn't dry? 
Your chicken is dry because you over-cook it. 195°F is far too high for chicken, I cook chicken breasts until they are 165°F and thighs to 175°F, but with thin slices it's very hard to get an accurate temperature with a probe so I'd check for doneness by cutting through it. Thin slices of chicken won't take more than a couple of minutes to cook thoroughly, if you put the slices in first by the time your peppers and onions are done the chicken's had all the goodness cooked out of it. Try cooking the peppers and onions first, then add the chicken when they are just getting done. Cook until they are just about done, then melt your cheese on. 