Good onion soup takes love and devotion. The onions take at minimum an hour, and often two hours, to get to the right stage of carmelization. I start with 5 or 6 large onions. Sometimes I get different types to mix together. They’re all delicious once they’ve been cooked forever. I slice them lengthwise and into half rings. Wide slices are fine. Cook them over medium heat — stir frequently for uniform cooking, and to prevent sticking —  until they’re dark brown but not burned and black. Add beef stock and red wine. You can thicken it with flour but I don’t.

Besides cooking the onions with lots of attention for over an hour, the other most important thing that I’ve found with onion soup is your choice in cheese. I used to just use Swiss cheese of any kind, but in the past few years I’ve realized that gruyere or emmenthaler is best. Mixing them is even better.

Then add about 8 cups of beef broth and a splash more of wine. Simmer a bay leaf for 15 minutes.
Cut a slice of crusty or hard bread and put the gruyere and/or the emmenthaler cheese on top. Broil it until bubbly and light brown.