I’ve NEVER had any luck reheating gravy on a stove top as it always dries out too fast!!! My preferred way to reheat gravy is in a microwave. I put the gravy in a small cup & then I add just a little bit of milk to the gravy to thin it out just a little. When I get ready to heat it, I put it on for 15 seconds at HALF power & then stir. Then I do consecutive 15 seconds at half power & then stir until it gets as hot as I need it to be. I very seldom have to do the 15 seconds more than 4 times.
Be aware that you can’t reheat gravy more than ONCE because it gets too thick. stiff, & lumpy, & it’s NOT good the next time you try to reheat it, so only reheat the amount you need at the time!!!
Dayum you…now I’m craving chicken & gravy & my KFC has already closed for the night…hope you ENJOY yours!!!