French Onion Soup Crostini

I love French onion soup, and, judging by the popularity of one of my earliest posts on a vegetarian version of the soup, so do you.

What’s better than the mix of savory, earthy broth with the sweetness of those wonderfully caramelized onions?  And, of course, let’s definitely not forget the melted cheese on top.  The soup version, though, does take a good deal of time to prepare (meanwhile making your entire kitchen smell like heaven…), so I have been looking for something that had all the flavor of French onion soup without all of the fuss.

Ladies and gentlemen, let me introduce you to these little French Onion Soup Crostinis.  Now, I know the name sounds weird, I will admit.  But I am calling them that because they TRULY do have all the flavor of the original soup.  I think that these would make an incredible appetizer for a more fancy get-together, or you could even pair them with the original soup.  All I know is that I made 12 of them, and I couldn’t stop eating them.  They are great to reheat in the oven as well.  At first glance, the mix of ingredients may sound  little strange, but I beg you to give them a chance.  You might be surprised…..

French Onion Soup Crostinis

Servings:  approximately 12 individual crostinis


1 French baguette (preferably as fresh as possible), cut on the diagonal about 3/4-inch thick or so

2 tablespoons olive oil

1 large yellow onion, thinly sliced

2 large shallots, thinly sliced

2 teaspoons garlic, minced (about 2 cloves)

2 cups fresh spinach

1/2 teaspoon dried thyme

Salt and pepper, to taste

2-3 tablespoons stone ground mustard (the stronger the better, in my opinion)

2 cups Gruyère cheese, grated


1. Preheat the oven to 425 degrees.

2.  In a large sauté pan over medium-high heat, heat the oil until shimmering.

3.  Once the oil is hot, add the shallots and onions.  Do not stir for about 3 minutes or so (you want them to start browning a little.)

4.  Cook the onions for another 10 minutes or so, stirring occasionally.

5. Add the garlic and cook for another 5-10 minutes, or until onions are well browned and caramelized.

6.  Add the thyme, salt, and pepper, mix well.

7.  Remove the onion mixture from the pan and place in a separate heatproof bowl.

8.  Return the pan to the heat and add the spinach, mixing well until wilted (about 1-2 minutes).  Remove the pan from the heat and set aside.

8. Spread your desired amount of mustard over each piece of bread and place each piece on a baking sheet.

9. Top each slice of bread with a few pieces of wilted spinach, onion mixture, and top with grated cheese.

10. Bake the crostinis for about 10 minutes, or until the cheese is completely melted.


Adapted from Whole Food Market.

February 18, 2011 - 6:04 am

Blog is the New Black - This is a wonderful idea. Def saving this one!

February 18, 2011 - 8:12 am

Eat Good 4 Life - Yum, Yummy….Never made this before, maybe I should, and soon……:-)

February 18, 2011 - 8:43 am

notyet100 - luv the topping,..:-)

February 18, 2011 - 9:01 am

Josie - The bread and cheese are the best part of French onion soup, so I am all over this! Yum!

February 18, 2011 - 10:49 am

Mom - these are very good. I couldn’t stop eating them!

February 18, 2011 - 12:34 pm

Georgia @ The Comfort of Cooking - This is so creative, Shanon! What a wonderful appetizer, and I bet absolutely delicious.

February 18, 2011 - 8:49 pm

Tweets that mention The Curvy Carrot » French Onion Soup Crostini -- - […] This post was mentioned on Twitter by Allium Sativum, Shanon Lacy. Shanon Lacy said: French Onion Soup Crostini. Yes, it tastes just like the soup version=delicious! […]

February 19, 2011 - 2:14 am

Jacqueline - Wow, this looks so good! The pictures are beautiful! What are you shooting with?

February 19, 2011 - 8:51 am

srlacy - Hi Jacqueline-

Thanks for visiting the blog!

Right now I am using a Canon Rebel DSLR with a Sigma 50mm Macro lens. I recently switched out the kit lens for the macro, and now I am basically using it for all the shots. I am also using a 430EX II Speedlite because the light here in Indiana right now is too blue for my liking-I cannot wait until the longer, more brighter days of summer!

Shanon 🙂

February 22, 2011 - 4:15 pm

natalie (the sweets life) - this is SUCH a good idea!!

March 8, 2011 - 2:34 pm

Lazy Day | Mon Mon's Nom Noms - […] to get some cheese in today, before I go FORTY days without it, so I haaaad to try this recipe from the Curvy Carrot!  I give you french onion soup […]

December 15, 2011 - 6:25 pm

Madison @ FatBurningFurnace - This is one of my favorites sandwiches but I don’t have a good recipe for it, so I am looking forward to trying it out. It looks amazing and better then my current recipe, which never comes out tasting right for some reason. Thanks for sharing it! I have you saved to my bookmarked.

February 5, 2012 - 5:01 am

The Curvy Carrot » Super Bowl Sunday Finger Food Recap - […] French Onion Soup Crostini […]

December 17, 2012 - 5:50 pm

Ambar - I have never tried onion soup but i’ve been wanting to try it for the longest! I hope it taste good! lol I will let you know how it comes out:)

August 27, 2013 - 1:31 pm

valeria brown - I can’t wait to try these