Celeriac Soup

Ingredients

• 60g / 4 tbsp butter, unsalted
• 2 garlic cloves, finely chopped
• 1 onion, diced (brown or yellow)
• 1/2 leek (white part only), diced into 1cm / ½" cubes (~ 3/4 cup, Note 1)
• 3 celery stems, diced into 1cm / ½" cubes (~1 1/2 cups)
• 800g / 1.6 lb (peeled weight) celeriac, cut into 2cm / ⅘" cubes (~1kg / 2lb unpeeled, Note 2)
• 200g / 7oz potato, peeled, cut into 2cm / 4/5" cubes (floury or all-rounder – about 1 large; Note 3)
• 1.5 litres / quarts (6 cups) water, or stock if you prefer
• 1 1/2 tsp salt
• 1/4 tsp white pepper
• 1 cup cream, full fat (pure, thickened or heavy, Note 4)
• 1 bay leaf, fresh
• 2 thyme sprigs
• 1/2 tsp black peppercorn (go without if no sachet)
• 1/2 tsp coriander seeds (1/8 tsp powder if no sachet)
• Croutons (Note 6)
• Olive oil, for drizzling
• 1 tbsp chives, finely chopped (sub parsley or chervil)

Steps

1. Spice and herb sachet: Bundle the bay leaf, thyme, black peppercorns and coriander seeds loosely in a small piece of cheesecloth to create a sachet. Tie with cooking twine to secure.
2. Cook onion and leek: Melt butter in large pot over medium-low heat. Add onion, leek, celery and garlic. Cook for 10 minutes until onion is soft but not golden. Don't rush this part – this creates an important flavour base so we can make this soup using water not stock.
3. Cook celeriac and potato: Add celeriac and potato. Cook for 10 minutes, stirring regularly, until the outside of the celeriac and potato starts to soften. Be careful to not colour the celeriac – we're going for a white soup here!
4. Simmer 25 minutes: Add salt, pepper, Spice and Herb Sachet, and water. Bring to a boil, then turn down to a simmer. Simmer for 25 minutes (no lid) until celeriac is very soft.
5. Cream: Add cream, simmer for another 3 minutes.
6. Blitz: Remove Sachet, then blitz until fully smooth using your method of choice: Stick blender (~ 3 mins), or cool slightly and do in a blender in batches (Note 5)
7. Adjust seasoning: Adjust salt and pepper to taste.
8. Serving: Ladle into bowls. Sprinkle with croutons and chives, drizzle with olive oil. Serve with crusty bread for dunking!