1.In a medium saucepan, bring the milk and water to a boil. Add salt and 3 tbsp butter. Simmer just until the butter melts.
2.Take off the heat and sprinkle in potato flakes.
3.With a whisk or fork, mix then whip up potatoes until fluffy.
4.Sprinkle pepper and 1 tbsp butter on top. Let melt into the hot potatoes. Enjoy!