I make dried beef treats for Riley. I get a boneless lean piece of beef like a bottom round london broil cut. Then I cook it in the oven till it's cooked thru. Then I let it cool a bit, slice it as thin as possible (I use an electric knife) put the slices on a rack over a cookie sheet and put back in the oven at 200 to 250 degrees and let it dry out. I can't remember how long it takes, about 2 hours maybe more. I guess that also depends on how thin you get the slices. Once its done you break it up into tiny pieces. It is a lot of work but it lasts a long time. It keeps well in the fridge.
I want to try the same thing with chicken, I heard partially freeze chicken tenders, slice very thin, then use the same drying technique in the oven. Some people use a dehydrator. I've heard dried chicken doesn't keep long so must be refrigerated or even frozen if not used shortly.