Spray inside of Crock Pot with cooking spray.
Dump the diced onions into the Crock Pot.
Place the chicken breasts in a single layer on top of the onions.
Dump the cream of chicken soup into a mixing bowl.
Add the gravy mix, water, sage, pepper and parsley to the bowl.
Whisk well.
Pour the mixture over the chicken breasts in the Crock Pot.
Place the lid on the pot and set it to cook on LOW for 5 hours.
After 5 hours remove the lid and stir the chicken and gravy well.
Break the chicken breasts apart as you stir.
Serve over mashed potatoes or rice.
