Ingredients

2 tablespoons olive oil

1 medium onion, chopped

Coarse salt and freshly ground pepper

6 cups peeled, chopped celery root (from about 2 large celery roots)

1 cup peeled and chopped Yukon gold potatoes (from about 1 potato)

10 cups homemade or low-sodium store-bought vegetable stock

2 cups peeled, cored, and quartered ginger gold apples (from about 2 apples), plus 1 apple, cored and sliced into thin wedges, for garnish

1/4 cup celery leaves or leaves from celery root stem, for garnish

Preparation

In a large heavy-bottomed saucepan, heat olive oil over medium heat. Add onion and season with salt; cook, stirring until onions are soft and translucent, 5 to 7 minutes. Add celery root, potato, and vegetable stock; reduce heat to medium-low and simmer until potatoes are soft, 15 to 20 minutes.

Add apples and continue simmering for 5 minutes. Remove saucepan from heat and puree using an immersion blender or, working in batches, using a conventional blender; season with salt and pepper. Serve immediately garnished with apple slices and celery leaves.