1. Cut the potatoes into thick slices.
2. In a saucepan, pour in the beef broth. Add the potato slices. Bring to a boil. Cover and reduce heat. Let simmer until tender when pierced with a knife. Remove the potatoes.
3. Preheat the oven to 400°F.
4. In a pan, melt the butter. Add the chopped onions. Cook for 4 minutes over medium heat.
5. Transfer the cooked onions to a baking dish. Cover with the potato slices. Pour the cream over the potatoes. Cover with grated cheddar cheese.
6. Bake for 10 minutes or until the cheese is melted. Remove from the oven and serve hot.