Preheat oven to 350F. Prepare a 9x13 casserole dish with cooking spray.
In a large mixing bowl, combine the cooked chicken, mayo, sour cream, heavy cream, bouillon, salt, pepper, and sage.
Toss to combine thoroughly.
Spread the mixture in an even layer in the prepared baking dish.
Bake at 350F for 30 minutes.
Carefully remove from the oven, Top with sliced cheese, making sure to cover the whole top of the casserole.
Cut the biscuits into quarters. Spread the biscuit quarters over the cheese, covering as much as possible.
Brush with melted butter.
Return to the oven and bake for 20 minutes or until the biscuits are golden brown and the internal temperature of the dish as reached 165F.
Remove and serve warm!