After dinner the other night, my wife got to wondering why French onion soup is the only one that seems to be served au gratin. A search for recipes brings up a lot of soups with “au gratin” in their names, but only French onion seems to actually be gratinéed - browned on top.
So are there any others? I’ve found soup recipes involving toast, but French onion seems to be in a class of its own.
(Incidentally, I came up with a variant that combines it with drunken mushrooms, and it’s pretty dang tasty. So I guess that makes two, but only technically.)
I can think of plenty that are/can be garnished with cheese (tortilla soup comes to mind, as do Italian ones like minestrone), or contain cheese as an ingredient (beer cheese, potato, etc… or using parmesan rinds in soups), but I can’t think of any others that are gratinéed.
Do a Google search for “soup with cheese crouton”. French onion soup comes up, but also cauliflower, tomato, and pumpkin. I’ve had both pumpkin and cauliflower soup served in restaurants with a cheese crouton. Cauliflower with cheese is a traditional recipe, so doing it with a cheese crouton is just a twist on tradition.