I mixed equal amounts of cooked sweet potato and raw ground turkey to make leather last year. Dogs loved it of course. Rolled the icky stuff between wax paper sheets to pie crust thickness [which made a very thin leather], peeled off the top sheet, in dehydrator until top was leathery, peeled off bottom, dry side down and finished drying. Stayed a pretty orange color and got lots of treats out of it since it was so thin. It wasn't too brittle, I wondered about that since there isn't any gluten in it. The fastest easiest treats are simply baking meat or organ and cutting into bits. Liver is great this way. I would experiment with different combinations of vegetables and ground meat. I am quite certain the only problem would be if the treat is hard to handle. Your dog will love anything you come up with. Try baking meat mixed with egg and potato for meatballs.