Season the chicken on both sides with salt, pepper and sage
Combine the potatoes, celery, onion, and carrots in the slow cooker and then rest the chicken on top. Add 1 cup of chicken broth and cook on low for 5 hours.
After 5 hours, remove the chicken and cool till you can handle touching it. Separate the skin, cartilage and bone from the meat and set aside.
Combine the can of soup and the remaining one cup of broth together until smooth and add it to the slow cooker along with the reserved chicken and mix well.
Prepare the Bisquick mix according to the package directions. After prepared, separate the dough into 5 portions and drop into the slow cooker gently, so they stay on top.
Mix the butter and sage together and gently brush the mixture over the biscuits.
Replace the lid and cook for another 1.5 – 2 hours or until the biscuits are cooked.