Spray a slow cooker with cooking spray. Peel and slice potatoes. Place them in an even layer in crockpot. (If using a regular crockpot, layer the potatoes and cheese mixture and additional cook time may be needed).
In a bowl, whisk together soups and evaporated milk. Pour over potatoes; stir gently.
Cover and cook on low setting for 4 hours, or until potatoes are very tender. Stir occasionally, if possible.