Root Vegetable Soup

Step 1

Melt butter in a large, heavy-bottomed pot. Stir in onion and celery. Cook, stirring occasionally, until vegetables are tender, about 10 minutes. Stir in garlic, rosemary and bay leaves; cook 1 minute more. Add root vegetables, 8 cups water, salt and pepper. Bring to a boil; reduce heat to medium and simmer, covered, until vegetables are tender, 30 to 40 minutes.

Step 2

Remove and discard rosemary branches and bay leaves. Using an immersion blender, purée soup until smooth. (Alternatively, you can purée the soup in batches in a blender or food processor.) If the soup is too thick, add a little water. Season with lemon juice and more salt to taste.

Step 3

To serve, ladle soup into bowls and top with a drizzle of olive oil, a few drops of lemon juice, flaky salt and crushed chile or grated cheese, if desired.