Melt butter in a skillet over medium heat.
Add flour and cook, stirring constantly, until smooth.
Gradually pour in milk, whisking continuously.
Bring to a simmer, stirring until thickened.
Stir in cream, salt, and pepper.
Assemble and Bake:
Preheat oven to 350°F (175°C).
Arrange sweet potatoes in a baking dish.
Pour creamy sauce over sweet potatoes.
Add Cheese and Finish:
Bake for 45 minutes.
Sprinkle with mozzarella cheese.
Bake for an additional 10-15 minutes or until cheese is melted and golden.
Garnish with chives and parsley.
Serve:
Let cool slightly before serving.
Enjoy hot.
