Preheat oven to 350 degrees.
Place boneless, skinless chicken breasts in sauce pan with enough water to cover the chicken. Bring to a boil, then turn off the heat; place a lid on your pot and allow to sit for 10-15 minutes to finish cooking.
Remove chicken from stock (reserve the stock) and allow to cool, then shred the chicken.
When building the layered casserole, do not mix the layers.
Layer 1 – In 9×13 or larger casserole dish, melt 1 stick of butter. Spread shredded chicken over butter. Sprinkle black pepper and dried sage over this layer.
Layer 2 – In small bowl, mix milk and Bisquick. Slowly pour over chicken.
Layer 3 – In medium bowl, whisk together 2 cups of the chicken stock (strained, if needed), chicken granules and soup. Once blended, slowly pour over the Bisquick layer.
Bake until the top is golden brown; approximately 50-60 minutes.