French onion soup is hearty comfort food. It has everything you might crave on a cold evening -- crusty bread, melted cheese, a rich broth and sweet, caramelized onions. The hardest part about making this dish is slicing up all those onions, so get ready for a good cry! Once all the ingredients have simmered together, top each crock of soup with a thick slice of crunchy French bread and then melt Gruyere cheese on top until it's bubbly and gooey. Yum!