Onion Soup

Right after graduating from undergrad, I was lucky enough to spend a month traveling around Europe. It was the first time I had been out of North America and it was a real adventure. In Florence we ate at a small family-run restaurant that we discovered by chance while wandering around one evening. I remember everything being lovely but I have never forgotten the onion soup I had that night. It was a puree of onion and at the time I thought it was the best thing I had ever eaten. That flavor has stayed with me all of these years and I have often lamented the fact that I didn’t record the name of that restaurant so I could go back.

I was excited to see this recipe for an onion soup in the most recent issue of Bon Appetit and hoped it would live up to my memory of that soup in Florence.

It did! Who knew that this was such a simple problem to solve? Caramelize some onions and puree them with some chicken stock. Perfection. The recipe below is actually a little fussier than that, but I think the take-away is the soup itself.

This recipe can be simplified in a few ways, which I outline below. Great as is, but in the future I will run with this idea and make it my own. You should too.

Onion Soup with Sage, Croutons and Grated Lemon Peel (adapted from Bon Appetit, March 2010)

  • 12 tablespoons (1 1/2 sticks) butter, divided
  • 24 cups thinly sliced onions (about 5 3/4 pounds)
  • 8 cups (or more) low-salt chicken broth (preferably homemade)
  • 1 1/2 cups 1/2-inch pieces torn crustless country-style bread
  • 16 fresh sage leaves
  • 1 1/2 tablespoons (or more) Sherry wine vinegar
  • 2 teaspoons finely grated lemon peel

Melt 6 tablespoons butter in heavy extra-large pot over medium-high heat. Add onions; sprinkle with salt and pepper and sauté until onions begin to soften, 15 to 18 minutes. Reduce heat to medium and sauté until onions are very tender and deep golden brown, stirring often and adjusting heat as needed, 25 to 30 minutes longer (this took me more like 45-50 minutes). Transfer 1 1/2 cups caramelized onions to small bowl and reserve for garnish.
Add 8 cups broth to remaining onions in pot and bring to boil. Reduce heat and simmer 25 minutes to blend flavors. Cool slightly. Working in batches, puree soup in blender until smooth. Return to same pot and add more broth by 1/4 cupfuls to thin soup to desired consistency. Season soup to taste with salt and pepper. DO AHEAD Can be made 1 day ahead. Cover and chill reserved caramelized onions. Cool soup slightly. Chill soup uncovered until cold, then cover and keep chilled. Re-warm caramelized onions and soup separately before continuing.
Melt 2 tablespoons butter in medium nonstick skillet over medium heat. Add torn bread pieces and sauté until bread pieces are crisp and golden, 5 to 6 minutes. Remove from heat and reserve.
Cook remaining 4 tablespoons butter in small saucepan over medium heat until golden brown, stirring occasionally, 3 to 4 minutes. Add sage leaves and cook until slightly crisp, 30 seconds to 1 minute. Transfer leaves to small plate; reserve brown butter in saucepan.
Stir 1 1/2 tablespoons vinegar into reserved caramelized onions, adding more vinegar by 1/2 teaspoonfuls, if desired.
Divide warm soup among 8 bowls. Spoon vinegar-seasoned caramelized onions atop soup in each bowl. Sprinkle each serving with croutons and fried sage leaves. Drizzle sage brown butter over each; sprinkle lightly with grated lemon peel and freshly ground black pepper and serve.

***What will I do in the future: I will make the soup and the croutons. I will top with a splash of sherry vinegar, salt, pepper and some lemon zest. I honestly don’t think the fried sage and brown butter are that important, though they are lovely if you are serving this for a fancy occasion.

20 comments to “Onion Soup”

  1. Do you have a recommendation for a non-meat stock? Would mushroom be better than just straight vegetable?

  2. Hey Jane, good question. I think vegetable would be best. If you are using store-bought, I would do half vegetable stock and half water, which would also be my recommendation if you use store-bought chicken stock. The onions are where most of the flavor is coming from so substitutions like this won’t be a problem.

  3. Great soup! will def try it

  4. Hello.
    Writing from far away, from Paris, neighbourhood close to the bio-market at blvd Raspail and two guys selling potatoes pancakes with cheese!. It is a pity that you do not write more often, as I like what you do.
    As regards fried sage, I am not a great fun of it, as it becomes a bit bitter for me. Otherwise, the soup is great.
    Can you really feel the taste of the Sherry vinegar in the soup?
    Sorry for mistakes, I am not a native speaker nor a translator :)

  5. Hello Magdalena! I know that market and those potato pancakes well, they are amazing. The sherry vinegar adds a nice brightness to the soup and complements the sweet caramel flavor of the onions. Thanks for writing!

  6. Tim, I know that you know, because I saw your pictures from visit in Paris, as I read this blog since a quite long time, but I didn’t dear to put my own comment. Have a nice day!

  7. i bookmarked that soup to make in the next week or so… i cannot wait! looks amazing!

  8. I’m wondering if a dollop of creme fraiche would be nice as well, sans the other toppings (except for the crutons—I love crutons), if one were to stray form the recipe a second go round.

  9. Yes! Maybe! Worth a try for sure, not sure it the creaminess of the soup needs more creaminess but in terms of flavor it might be nice. I would still do a shot of sherry vinegar. Will try next time. (which will likely be this weekend)

  10. The most mouth-watering recipe I’ve seen today. And I’ve seen a lot. Dammit, Tim! How am I supposed to make it through the afternoon with this soup drifting around my head? ;)

    I don’t know what I like more: this recipe, or the photos of your reflection hiding in the spoon. xo

  11. Erin in Sacramento says:

    March 10th, 2010 at 2:34 pm

    As a loyal reader of yours I get such joy out of seeing the things we have in common! I actually made that whole menu having just received my Farm Fresh to You box of organic produce so I could use lemons, kale, onions, potatoes, and chard. The soup was so flipping good we were all so surprised. It was the hit of the menu. We decided what made it so good was using chicken stock rather than beef (a first for me with onion soup-why such a revation? Who knows.) and blending the soup. And I, for one, can’t skip that brown butter. I’d make it if I were standing alone in my kitchen eating the soup from a cup. :-)

  12. This recipe is on my list for the week. I am even more excited to try it now after your review.

  13. Seeing as how there are few things in life better than caramelized onions, I am going to have to try this. This way maybe I can get a little glimpse of your delicious experience in France.

  14. i saw this too and it sounded awesome. just wasn’t in the mood to tote home all those onions, let alone thinly slice all of them, but now i’m a little more tempted :)

  15. Hey Erin! Great minds cook alike…or something? You are very ambitious to have cooked that whole meal, I can’t imagine. Glad to hear you liked the soup too.

  16. It’s interesting to me that you needed more time to caramelize the onions. I find that that’s ALWAYS a problem for me, even when I’m using a highly-tested recipe like something from Cook’s Illustrated. It always makes me avoid ’em.

  17. onion soup is such a wonderful pleasure! i confess i wish you remembered the name of that restaurant….i am heading to italy for 5 weeks in late spring and plan on eating my way through the country. maybe i’ll get lucky enough to stumble upon it!

  18. Yum! What a unique onion soup…blended! And with the most simple ingredients that are always on hand! Thanks!

  19. Aussiechick says:

    March 15th, 2010 at 7:50 pm

    We have a product in Australia called Massel stock cubes. They are a non animal derived Chicken/Beef & Vegetable (duh!) stock cube. They are fantasic I have used them since I worked in a Vego Cafe in the 90’s and they would be perfect for this and any other soup/stew

  20. Tim -So glad to see that you liked our recipe! We added a link to your post from the recipe on our site so that our readers can see your version and your insights. Hope that’s ok with you. Thanks again! -Emily, BA Web Editor


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