Wash, de-stem, and chop mushrooms
Spray the bottom of the slow cooker and place the chicken in one layer.
Sprinkle on the salt, pepper, and garlic.
Pour the mushrooms and wine over the top.
Cover the Crockpot and cook on LOW for 5-6 hours.
Remove the chicken with a slotted spoon.
In a separate bowl, make the slurry with the water and cornstarch.
Pour the slurry into the liquid inside the slow cooker.
Replace the chicken and cook on HIGH for 30 minutes or until the sauce is thickened.
Serve warm over rice.