Creamy Mashed Potatoes

Ingredients
3 lb. , mixed potatoes, such as russets & Yukon Golds
Kosher salt
1/2 c. , (1 stick) butter, plus 2 tablespoons for garnish
1/2 c. , milk
1/2 c. , sour cream

Ingredients
5 pounds Yukon Gold potatoes (aka: gold, butter)
2 cups milk or half and half
1 stick (8 tablespoons) salted butter
1 teaspoon salt (plus more for water and to taste)
1/4 - 1/2 teaspoon black pepper (plus more to taste)

Ingredients
4 lbs potatoes (Yukon Gold or Russet )
6 tbsp butter (unsalted, at room temperature)
1 cup milk (or cream)
1 tsp salt
1/2 tsp pepper (black or white)