Cook green beans until nearly done. Let the liquid in which they cook reduce to a few tablespoons. Place the beans in a shallow casserole, and sprinkle with salt and pepper and a dusting of flour. Cover them with a layer of onion rings shaved paper thin. Make a light sauce of butter, flour, and the bean liquid. Pour over the beans. Add cream and sprinkle with grated Swiss cheese and buttered breadcrumbs and a few dots of butter. Bake in a hot (400 degrees F) oven until bubbly.