This simple gratin of brussels sprouts and bacon is made with only six ingredients plus salt and pepper, and you can easily make it low carb by eliminating the bread crumb topping. The brussels sprouts are cooked and then baked with bacon, butter, cream, and an amazing bread crumb and cheddar topping. We used 3 strips of bacon in the gratin, but feel free to omit the bacon or use more, depending on your tastes. Sliced sauteed mushrooms would make a delicious addition to the dish as well.