Pre-heat oven to 350F (180C). Lightly butter an 8 inch (21 cm) baking dish.
Peel and thinly slice the potatoes. Soak the potatoes in cold water for approximately 30 minutes, drain well and pat dry.
Grate the Fontina.
In a medium pot melt the butter, add the flour, whisk until smooth, add the milk and continue whisking add the salt and pepper and continue whisking until thickened (just until bubbles start to appear) remove from heat. (If too thick add a little milk).
In lightly buttered baking dish add a layer of potatoes (⅓ of the potatoes), sprinkle with half the grated cheese and ⅓ of the white sauce, another layer of potatoes, last half grated cheese, ⅓ white sauce, last layer of potatoes, white sauce and sprinkle with the freshly grated Parmesan cheese. Bake covered for 45 minutes, uncover and continue cooking for approximately 15-30 minutes, or until tender. Let sit 5-10 minutes before serving. Enjoy!
You may want to broil the potatoes for 2-3 minutes in order to brown the top.
Notes
Leftover potatoes can be stored in an airtight container in the refrigerator for up to 3 days. While it is possible to freeze leftovers, potato texture may change when thawed. It will last up to two weeks in the freezer.