Grease an 8x8-inch casserole dish with butter and evenly layer the Simply Potatoes.

In a medium saucepan, combine milk, heavy cream, kosher salt, dry mustard, black pepper, and nutmeg. Heat over medium, stirring constantly until it nears a boil, about 5-7 minutes.

Lower the heat to medium-low and stir in the shredded sharp cheddar cheese until it melts and the sauce is smooth, about 3-5 minutes.

Pour the warm cheese sauce over the potatoes and gently stir to coat them evenly.

Dot the surface with small pieces of butter and sprinkle paprika over the top.

Cover with plastic wrap and chill in the refrigerator for at least 12 hours.

Preheat the oven to 350°F (175°C). Uncover and bake for approximately 45 minutes until golden brown and bubbling.