Preheat oven to 200 degrees C. Lightly grease with cooking spray a large baking dish.
Place a layer of sliced onions on the bottom of the dish then add a sprinkle of French onion soup mix, then add a layer of bacon pieces, followed by a layer of potato slices, a layer of grated cheese then top with a pouring of cream.
Continue adding alternate layers of all ingredients until finished and top with a final layer of grated cheese.
Spray a piece of aluminium foil with cooking spray then cover dish and place in the oven for 40-50 minutes.
Remove foil then continue to bake for a further 10 minutes or until nicely browned and bubbly.