only slightly mounded.
Scatter the remaining butter pieces evenly over the potatoes. Sprinkle the kosher salt over the top so it seasons the potatoes and the cooking liquid.
Slowly pour the can of evaporated milk over the raw potatoes in the slow cooker, making sure the milk drizzles down through the gaps between the potatoes. The potatoes will not be fully submerged; that’s fine, as they will release moisture while cooking.
Cover the slow cooker with the lid and cook