This yummy soup has a combination of complex flavors that are enhanced when you wait a few days to eat it. Don’t get me wrong, it’s good the first day but so much better warmed on the second or even third day. Greg has been eating this soup for 3 days now and he commented last night that it’s the best soup I’ve prepared.
I actually decided to make this soup when I realized how many yellow onions I had left over from the holidays. I hate to see food go to waste and with just the two of us in the house, there are not a lot of meals I can make that will use up that many onions before they spoil. So, I decided on the onion mushroom soup below. I had prepared it before and simplified the ingredients quite a bit from the original Bon Appétit recipe.
In my opinion, what makes this soup so delicious is the combination of both beef and chicken broth along with both white wine and brandy and allowing the flavors to meld over time. Make sure you’re patient with the onions and allow them to truly caramelize over very low heat.
French Onion and Mushroom Soup

Inspired by Bon Appétit, Feb 2002
Makes 6 servings
- 3 tablespoons butter
- 1 1/2 pounds yellow onions (not sweet) halved, thinly sliced (about 5 cups)
- 4 fresh thyme sprigs
- 1 1/2 pounds sliced mushrooms, stemmed
- 5 tablespoons Cognac or brandy
- 3 garlic cloves, minced
- 3 cans beef broth
- 2 cans chicken broth
- 1 cup dry white wine
- Toasted white bread sliced into triangles
- Sliced Mozzarella cheese
Melt 1 tablespoon butter in heavy large pot over high heat. Add onions and thyme; sauté until onions begin to soften, about 8 minutes. Reduce heat to very low; cook until onions are caramelized, stirring occasionally, about 30 minutes. Transfer onion mixture to medium bowl.
Melt remaining 2 tablespoons butter in same pot over medium-high heat. Add mushrooms; sauté until soft, about 12 minutes. Add brandy and garlic; stir 20 seconds. Stir in onion mixture, then broth and wine. Bring to boil. Reduce heat to low; simmer until onions are very tender, about 45 minutes. Discard thyme sprigs. Season soup with salt and pepper.
Preheat broiler. Place bread slices on large baking sheet. Lay sliced cheese on bread, dividing equally. Broil croutons until cheese begins to brown in spots, about 30 seconds. Divide soup among 6 bowls. Top with croutons and serve.

Yum! That looks really good. I’ll try it soon. I love soup, especially when it’s so cold!
Maryse
I have the same onion dilemma …thanks for the soup idea. It looks real tasty and will get me motivated to back some bread!
Onion soup is one of my favorites. This one sounds really good. I like that there are mushrooms in it also.
Oh wow. French onion is my hands-down favorite soup but the addition of mushrooms, which I adore, would just make this heavenly. I am definitely trying this.
Angie,
Great article on pea soup. Your comment about the ham hole made me laugh. The recipe for mushroom (something) soup from Colorado sounds yummy, Love, Peg
This looks fantastic!
How much broth is a can? I usually use homemade, and it comes in cartons in the grocery store.
I also prefer homemade! The cans are 14 ounces. Enjoy!
I Made this soup last week …. it’s really delicious – thanks for sharing the recipe – I’ve never thought to add mushrooms to french onion soup, they are a fabulous addition!
Thank you for trying the soup – I am so happy you enjoyed it! the mushrooms really add a nice earthiness to it and I really enjoy it this way. In fact, I’ll have a difficult time making it any other way again.
I happened upon this yesterday looking for a recipe with onions AND mushrooms. I decided it was a recipe worth trying. And, boy was I right! It was full of flavor! It’s def a keeper!
Thanks for commenting Natasha. It reminded me to make this soup again soon. I have some leftover rib bones with meat on them and think I’ll be making some beef broth in the next few days.
Made this yesterday and it is yummy! I didn’t have thyme, so I used rosemary as it’s one of my fave flavours, and it turned out great.
I am so glad you enjoyed it. Rosemary would be a great add…I’ll try that next time!