Have you perfected the grilled cheese sandwich? If you yearn for something a little more exciting than American cheese on white bread, Ruth Reichl, former editor in chief of Gourmet magazine, has a few ideas. From not skimping on the butter (or mayo!), to additions like shallots or garlic, these tips may lead you to your best grilled cheese ever.That's right: Reichl recommends adding finely chopped onions, shallots, and scallions. Yep, she mixes a small amount of each of them! She also swears by grated cheese, lots of butter (never margarine), and a swipe of mustard for extra tang. Oh, and if you do decide to grate your cheese, sprinkle some on the outside of the bread for a crunchy twist.