This simple country potage gets the luxury treatment with the addition of shaved winter truffles. If celeriac is unavailable, jerusalem artichokes or even starchy potatoes make a fine substitute for the bittersweet root vegetable.
- Large Pot
- Blender or Immersion Blender
- Large Plate or Baking Sheet
- Paper Towels
- Large Skillet
- Small Bowls
- 2 lb. celeriac, peeled and cut into medium pieces (3¾ cups)
- 8 oz. leeks (white parts only), rinsed well and coarsely chopped (2 cups)
- 2⅔ cups chicken stock
- 5 Tbsp. salted butter, divided
- 1 Tbsp. (1 oz.) shaved winter truffle (fresh or canned), plus extra for garnish
- Fine sea salt
- Freshly ground white pepper
- 4 medium slices country white bread, crusts removed and cut into ½-inch cubes (2 cups)
- 6 oz. grapeseed or vegetable oil
- 1 medium garlic clove
- To a large pot over high heat, add the celeriac, leeks, chicken stock, and enough water just to submerge the vegetables. Bring to a boil, then lower the heat to simmer and cook until the vegetables are very tender, 30–35 minutes. Remove the pot from heat and either transfer its contents to a blender or use an immersion blender to purée until very smooth. Stir in 4 tablespoons butter and the truffle, and season to taste with kosher salt and white pepper. Return the soup to the pot to keep warm until you are ready to serve.
- Line a large plate or baking sheet with paper towels and set it aside. In a large skillet over medium-high heat, heat the grapeseed oil until it is nearly smoking. Add the garlic and bread and cook, stirring frequently, until lightly browned and crispy all over, 5–6 minutes. Remove from heat, immediately add the remaining tablespoon of butter and continue stirring to coat. Transfer the croutons to the lined plate to drain and season to taste with kosher salt.
- Ladle the soup into small bowls, drizzle with olive oil, top with a few croutons and truffle shavings, and serve hot.