Combine potatoes, milk, and 2 teaspoons of salt in a large saucepan or Dutch oven.
Bring the mixture to a simmer over medium heat. Reduce heat to low and cook, uncovered, stirring often. Cook until the potatoes begin to fall apart and most of the milk is absorbed (about 40-50 minutes).
Remove from heat, add butter, and mash the potatoes until smooth. Thin with additional milk if necessary.
Adjust seasoning with salt and pepper. Serve warm and enjoy!
Pro Tip: Avoid low-fat milk, as it can break during simmering. Whole milk ensures a creamy texture without splitting.