Cooked bacon adds smoky flavor to the cheese and bread crumb topping in this flavorful and creamy macaroni and cheese casserole. Feel free to make it without the addition of green onions. I thought they went well with the bacon flavor, but if you're not a fan of onions, you can leave them out. Serve this macaroni and cheese with sliced tomatoes or a tossed salad for a satisfying family meal.