Spray the insert of a medium slow cooker with cooking spray. Layer half each of the potatoes, bell pepper and ham. Sprinkle with half of the onion.
In a medium bowl, mix Alfredo, milk and pepper; spoon half of the Alfredo mixture on top. Layer with the remaining potatoes, ham and bell pepper. Then the onion, sprinkling evenly. Pour the remaining sauce mixture on top. (Do Not Stir) Cover with lid and cook on low heat for 6 to 8 hours.
About 5 minutes before serving, stir mixture gently. Then sprinkle with the parmesen cheese and replace lid until cheese has melted. Top each serving with the parsley! ENJOY