Homemade Mashed Potatoes | Bushwick Potato

Ingredients

• 2 pounds Yukon Gold potatoes , peeled, knots removed, and diced into 1 1/2-inch cubes
• 1 1/2 tablespoons Kosher salt , divided
• 6 tablespoons unsalted butter (4 diced, 2 sliced)
• 1/2 cup sour cream
• 1/2 cup whole milk , hot
• 2 teaspoons Dijon mustard (or horseradish)
• 3/4 teaspoon freshly ground black pepper
• finely chopped parsley , for garnish