Melt the butter in a large skillet, add the onion, celery and bell peppers and cook over medium heat until the vegetables begin to soften, and the onions become translucent.
Add the mushrooms and cook for another 2-3 minutes.
Stir in the soup mixture, then stir in the sour cream or heavy cream, and then dried parsley.
Then stir in the turkey. Heat gently until everything is warmed through.
Serve over cauliflower rice, spaghetti squash or low carb biscuits if desired.