Preheat the oven to 350 degrees. Add the stick of butter to a 9x13" baking dish, and place it in the preheating oven just until melted. Spread the chicken evenly out over the bottom of the dish. Salt & pepper the chicken layer, to taste.
3 chicken breasts, 1 stick butter, salt & pepper
Do NOT MIX the layers, and follow the steps exactly. In a small mixing bowl, whisk together the bisquick, half & half, and thyme until evenly combined. Slowly pour the mixture evenly out over the chicken, so as not to move the chicken around.
2 cups bisquick, 2 cups half & half, 1/2 tsp ground thyme
In another mixing bowl, whisk together the broth, soup, poultry seasoning, garlic, & onion powder until evenly combined. Again, slowly pour this mixture evenly out over the bisquick layer- again careful not to disturb it too much.
2 cups chicken broth, 1 10.5 oz can cream of chicken soup, 1/2 tsp poultry seasoning, 1/2 tsp garlic powder, pinch onion powder
Bake the casserole at 350 degrees for 50-60 minutes, or until the casserole is set and the top has formed a gorgeous golden browned crust.