Place butter, mushrooms, onion, and garlic in your crockpot.
In a mixing bowl, whisk together the broth, sour cream, ketchup, Worcestershire sauce, black pepper, and paprika until smooth.
Pour the mixture over the mushroom and garlic base in the crockpot.
Set your slow cooker to “low” and cook for 7 1/2 hours. During this time, the mushrooms will release their juices and create a rich sauce.
After 7 1/2 hours, add the cream cheese and fresh spinach to the slow cooker. Stir gently but thoroughly.
Continue cooking on “low” for an additional 30 minutes or until the cream cheese is fully melted and the spinach is wilted.
