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.