
Preheat oven to 350º F and lightly grease a 9x13-inch baking dish with non-stick spray.
In a medium bowl, whisk together 1-2 cans of soup (depending on how creamy/sauce you want this to be), milk, garlic powder, onion powder, rosemary and thyme, then season with salt and pepper.
Spread mashed potatoes into an even layer in greased baking dish, then top with shredded chicken.
Pour “gravy” sauce over chicken, then top with cheddar cheese, if using.
Place baking dish in oven and bake for 25-30 minutes, or until hot and bubbly.
Remove from oven and let cool 5-10 minutes before serving.