Swiss Potato Gratin

4 large russet potatoes, rough peeled and thinly sliced
1 cup grated swiss cheese
2 green onions, finely chopped
Salt and freshly ground pepper
1 cup heavy cream (you may want to use a little more than this, also, I have just used regular whipping cream instead of "heavy" cream, and it works fine)

Preheat oven to 375 degrees.
Spray 9x13 pan with vegetable spray. Layer potato slices, cheese, and onions. (2 or 3layers) Season with salt and pepper and then drizzle the heavy cream over the top. Cover with foil and bake for about 45 minutes. Then remove foil and cook about 10 minutes or so longer until the top gets a little brown.