2 tbsp (30 ml) olive oil 1 tbsp unsalted butter (optional) 1 large leek, white and light green parts only, thinly sliced and rinsed 2 garlic cloves, sliced 1 lb (450 g) celery root (celeriac), peeled and diced 1 large Granny Smith apple, peeled, cored, and diced 1 / 2 tsp smoked paprika (or a pinch of smoked salt) 1 / 2 cup (120 ml) dry white wine 4 cups (960 ml) low-sodium chicken or vegetable stock 1 bay leaf 4 sprigs fresh thyme (or 1 / 2 tsp dried thyme) 2 tbsp prepared horseradish (not creamy), or to taste 1 / 3 cup (80 ml) crème fraîche or plain whole-milk yogurt 1 tbsp fresh lemon juice, plus more to taste Kosher salt and freshly ground black pepper to taste Garnish: matchsticks of green apple, chopped chives, and a drizzle of olive or chive oil
Warm the olive oil and butter in a medium pot over medium heat. Add the leek with a pinch of salt and cook, stirring, until soft and translucent, 4–5 minutes. Stir in the garlic, diced celery root, diced apple, and smoked paprika; cook 2–3 minutes until fragrant. Pour in the white wine and simmer until reduced by about half, 2–3 minutes. Add the stock, bay leaf, and thyme. Bring to a simmer, cover partially, and cook until the celery root is very tender, 18–22 minutes. Remove and discard the bay leaf and thyme stems. Blend the soup until silky smooth (use an immersion blender or carefully in batches in a blender). Return to the pot. Stir in the horseradish and crème fraîche. Add the lemon juice, then season with salt and plenty of freshly ground black pepper. If needed, thin with a splash of stock or water. Do not boil after adding dairy and horseradish; gently warm through. Ladle into warm bowls and garnish with green apple matchsticks, chives, and a light drizzle of oil. Serve immediately.
To get nutritional information, press the Get Nutrition Info button below.