I can personally vouch for a few places around town (see my notes below), and a little research uncovered a winter’s worth of steaming crocks to try (also noted below).
Truffles: The recipe has always been a variation of Famous Barr’s legendary iteration, but the soup base is house-made veal stock. The cheese is a blend of Gruyère and Emmentaler, and the croutons (now wisely cut in chunks, so the soup is easier to scoop) are cut from a baguette from the Butchery Market.
: The cups are served in dainty French ramekins and the bowls in handled crocks, with Gruyere cheese spilling over the edges.
Herbie’s: The onion soup program has 40-year-old roots (“born in the Balaban’s days”). It includes beef stock, deeply caramelized yellow onions, red wine, and a little thyme. Executive chef Karl Schloz adds a few other components, such as a splash of demi glace, a hint of garlic, and a touch of sherry vinegar.
Brasserie by niche: Devotees claim Brasserie serves the best version in town, thick and loaded with onions. Thankfully, the white crock is always full to the brim…