Preheat the oven to 400 degrees.
First, spread the softened butter all over the bottom and sides of the baking dish. Next layer the potato slices on top of the butter covering the bottom of the baking dish.
Sprinkle the potatoes with one third of the parmesan and one third of the Swiss cheese. Season with a pinch of salt and pepper.
Repeat potato, cheese, salt and pepper layering twice more.
Add the half and half, pouring evenly over potatoes and cheese until the liquid is three quarters of the way up the sides of pan.
Reduce oven to 375 degrees and bake for 45 to 50 minutes. Remove from the oven and let it cool to room temperature then let it rest in the refrigerator overnight. As the potatoes rest their flavor will grow, plus it is very easy to cut them into portions when they are still cold from the refrigerator.
The next day cut it into single serving sized portions and reheat in the oven at 350 degrees for 15 minutes.
Serve it along your favorite cut of steak, pork or chicken.
I like a little al dente texture for my potatoes, but if you like them super soft, I would propose you increase the cooking time to one hour and the re-heating time to 30 minutes.
6 ounces parmesan cheese, grated
6 ounces Swiss cheese, grated
½ teaspoon salt
½ teaspoon pepper
2 cups half and half
1 tablespoon softened butter
3 large baking potatoes, peeled and sliced ¼ inch thick