Slow Cooker French Onion Soup

I always use home made beef broth from beef short ribs or prime rib bones, and I add wine to the onions plus Brandy or cognac for incredible flavor. Always use Gruyere cheese and a tip, I often put the bowls in a deep roasting pan as it's easier to get them out of the hot oven after broiling the cheese.

Toast the bread first and melt some of the cheese on it before topping bowls.

I thought there was Sherry in onion soup. Is that not right?

To answer Ron's question (and, frankly, mine as well) I did some research. According to the Epicurious website, and I find them a VERY reliable source for anything relating to cooking, they experimented with red, yellow, and Vidalia onions. They found that the Vidalias, cooked low and slow with a sprinkle of salt and sugar for caramelizing, was the best choice for a sweet, nutty and silky result. I hope that this helps.

Thanks for the recipe and wine suggestions from the comment. Pairing the soup with the right wine in your glass also enhances the flavors.
I was wondering, what is the best type of onion to use for onion soup?

We use some Brewer's Yeast, and yes a good splash of Old Vine Zinfandel with the onions to deepen and enhance flavor. Home made Beef stock is the best and yes make sure it's Gruyere. Go BIG flavor, or go home. . .

If it doesn’t have wine it’s not French onion soup thank you

I used BOXED beef broth (consume) rather than the bouillon (which makes it rather too salty in my opinion) and think it would be even better with homemade beef broth. Plus it has to be Gruyere cheese - it's the right flavor and melting point. It's a nice idea, making it in the crock pot, the recipe just needs a little tweaking. jh