Classic Delmonico Potatoes With Creamy Cheese Sauce - Quickie Recipe

Ingredients

• 3 lb (1.36 kg) Yukon Gold potatoes, peeled and cut into 1/2-inch cubes
• 1 tablespoon kosher salt, for the cooking water
• 1 tablespoon unsalted butter, for the baking dish
• 3 tablespoons (42 g) unsalted butter
• 3 tablespoons (24 g) all-purpose flour
• 1 1/2 cups (360 ml) whole milk
• 1 cup (240 ml) heavy cream
• 1 teaspoon dry mustard
• 3/4 teaspoon kosher salt
• 1/2 teaspoon white pepper
• 1/4 teaspoon ground nutmeg
• 6 oz (170 g) sharp white cheddar cheese, freshly shredded
• 2 oz (55 g) Parmesan cheese, finely grated
• 3/4 cup (45 g) panko breadcrumbs
• 2 tablespoons (28 g) unsalted butter, melted
• 1 oz (28 g) Parmesan cheese, finely grated
• 2 tablespoons chopped fresh chives or parsley