In a small saucepan, melt butter. Stir in the flour, salt and pepper until smooth. Gradually stir in milk. Bring to a boil; cook and stir for 2 minutes or until thickened.
In a greased 3-cup baking dish, layer half of the potatoes, fontina cheese, white sauce and chives. Top with remaining potatoes, fontina, sauce and chives.
Cover and bake at 400° for 30 minutes. Uncover; sprinkle with Parmesan cheese. Bake 10-15 minutes longer or until potatoes are tender and top is lightly browned. Let stand for 5 minutes before serving.