Poor celery. It’s such a behind-the-scenes vegetable. Important for mirepoix, but not the star; necessary for adding texture to chicken or tuna salad, but not the star; a crucial vehicle for cream cheese or peanut butter in ants on a log, but not the star. When will celery be the center of attention? Right now! In this surprisingly hearty celery soup, which I’ve been making all winter, celery is the star. Well, kind of.
It was, until I thought horseradish croutons might be a nice thing to try.
Lucky for us, celery doesn’t mind sharing the stage, and so it will here, once more– but it definitely gets equal billing with those fabulous croutons. This is not the celery soup you reconstitute from a can or mix into casserole. Without an ounce of dairy, this soup is silky, nuanced, comforting and incredibly flavorful. There’s a reason we use celery as a base layer in so many classic dishes– it’s delicious! With a few key ingredients to support and deepen the flavor– bacon for saltiness and crunch, shallots for sweetness– celery soup has quickly become one of my very favorites.
Now that horseradish is in season and abundant in the market, I look for an excuse to use it whenever possible. As I reached for the bacon to start a pot of celery soup, I noticed the horseradish root I had in the refrigerator and remembered how much I love those two flavors together. I came up with the idea of making croutons flavored with horseradish to add another layer of flavor to my soup. Was that ever a good idea! The croutons, as they soak up warm soup, soften to add another element of creaminess; the hint of sharp horseradish complements both the bacon and the sweet, grassy celery. It’s such a craveable combination of flavors, colors, textures… I just love this soup. The croutons are great on their own, too, added to a nice spring salad or made smaller to top a casserole with chicken, or macaroni and cheese.
Once you make this soup, you’ll never think of celery quite the same way. Just writing about it has me craving a bowl… I hope I have some bread for more croutons!
Celery Soup with Horseradish Croutons
For the croutons:
- 2 T. unsalted butter
- 1 T. olive oil
- freshly ground black pepper
- 1/4 tsp. kosher salt
- 1-2 T. freshly grated horseradish, to taste*
- 1/2 tsp. cider vinegar
- 3 c. day-old bread, cut into large cubes
For the soup:
- 2 pieces thick-cut bacon, cut into small pieces (lardons)
- 1/3 c. minced shallot, from one large shallot
- 3 c. diced celery, from about 6 stalks
- a scant handful of celery leaves, minced (optional)
- 6 c. chicken broth
- salt & pepper
Start by making the croutons, up to 2 days in advance. Preheat the oven to 375 degrees and cover a baking sheet with parchment or tin foil. Add the butter and olive oil to a small saucepan and warm over medium heat just until the butter is melted. Remove from the stove and add the pepper, salt, cider vinegar and freshly grated horseradish; stir to combine. Spread the cubed bread on your prepared pan and slowly drizzle half of the butter mixture over the top. Use a spatula to flip and stir the bread, then drizzle the remaining butter over the top. Bake for 10-12 mins., stirring and flipping the bread cubes after 5 mins., until the croutons are golden brown and slightly crisped. Set on the counter to cool while you make the soup.
Heat a large saucepan or Dutch oven over medium-high heat. Add the lardons of bacon and cook, stirring occasionally, until crispy. Use a slotted spoon to remove the bacon from the pan to a towel-lined plate; set aside. If you have more than 2 T. (estimated) of bacon fat left in the pan, pour off the excess; if you have less, add olive oil to make up the difference. Add the minced shallot to the pan and lower the heat to medium; cook for about 3-5 mins., until softened and fragrant. Add the celery, and leaves if using, to the pan and stir; cook for an additional 5 mins. Add a splash of broth to the pan and use a wooden spoon to gently scrape any good browned bits off the bottom, then add the rest of the broth. Bring to a boil, lower the heat back to medium-low and cover; simmer the soup for 20 mins. Remove from the heat and use an immersion blender (or carefully transfer to your Blendtec or equivalent) to process the soup until it is silky smooth. If you are concerned about strings from the celery, pass the soup through a mesh strainer at this point. Return to the pan and warm gently, just until heated through. Add salt & pepper to taste; keep in mind that both the bacon and croutons will add salt, so be judicious.
To serve, ladle a generous amount of soup into each bowl. Float 5-6 croutons (or as many as you like) in the center and top the croutons with some reserved bacon. Serve immediately. If you have leftovers, you can add the reserved bacon to the soup and refrigerate, but keep the croutons separate.
*I am a horseradish fiend and like a lot. Start by adding 1 T. horseradish to the mixture, let it sit for a moment, and taste with a piece of cubed bread. If you want a stronger flavor, add more horseradish. 2 T. is perfect for me, but horseradish can be very strong or very mild, root to root. It’s always a good idea to taste your food and make adjustments.