I LOVE french onion soup. The real stuff. Not from an envelope, sorry.
So the week before Christmas, I chopped 5 lbs of sweet yellow onions, two bunches of green onions, two leeks, and a handful of chives. I then crushed 4 cloves of garlic and threw all this together into my larger crockpot. I carried this out to the detached garage and plugged it in, set for high and 8 hours.
Once an hour I went out to the garage and stirred the pot. The onions were sweating down for the first 2 hours.... But then that magical change started, the thing all foodies love...carmelization. That point when the sugars start to chemically change and darken, causing flavor complexities to explode, I love carmelization! Once the onions had fully carmelized after 8 hours, the whole back yard smelled like rich onioney goodness! (Now do you know why I didn't do this in the house???)
Mash about half the onions and add a qt of chicken stock, one quart of beef stock, a sprig of thyme and another of rosemary. Let this simmer on low for about half an hour, without breaking a boil. Correct with salt and pepper to your preference.
Easiest french onion soup recipe from scratch I have ever seen. Much easier than sweating the onions on the stove in a giant skillet....that's almost an hour of nonstop stirring and you have to have laboratory quality control of your heat source. Plus, it doesn't leave your house smelling like onions for 6 months.