Its a hard choice, but i think that french onion soup just might be my favorite soup out there. Its like a magic trick the way it transforms a pungent onion into something savory and almost sweet. The crusty bread, nutty and melty gruyere, and beefy broth dont hurt matters either together, those components make a total winner of a soup, which is why we thought we might take those same components and turn them into a casserole With a higher ratio of crusty bread to caramelized onions, this casserole is a heartier take on the classic soup and its every bit as delicious.