Spray crockpot with non stick spray, or line it with a plastic liner.
In a bowl combine wine, stock, soup, thyme, salt, pepper and parmesan cheese.
Place chicken in crockpot. Place mushrooms and onions on top and around the chicken. Pour the soup mixture over everything.
Cook on low 5-7 hours, depending how hot your crockpot cooks. Chicken is done when it shreds easily with forks.
Shred chicken and stir in spinach. Continue to cook on low another 15 minutes.
Serve over rice.