This is a regular dish in our household! My kids loved it and quickly ate up the leftovers the following morning!

4 large russet potatoes, peeled and cubed
1/2 cup whole milk
1/4 cup unsalted butter
1 cup shredded cheddar cheese
1/2 cup sour cream
Salt and pepper to taste
1/4 cup grated Parmesan cheese
1/4 cup breadcrumbs
1 tablespoon chopped fresh chives (optional)