This is a surprisingly elegant and flavorful, subtle soup. There are different possibilities to prepare this soup: roast the sweet potato first and use the leek raw in the soup (a perfect balance of sweet and tangy), use both sweet potato and leek raw (a more tangy, light soup), or roast both leeks and sweet potatoes first (a soup with a sweet depth). Leeks have a definite onion-y tang and balance out the sweetness of the sweet potatoes. Anyone who has bbq-ed leeks knows that they become vegetable candy sticks once they are roasted with a very mild onion tone.
For this soup, I roasted both the sweet potato and the leeks, and added a small piece of celeriac raw. The soup cooked for 20 min in home-made chicken stock and a cup of milk. The flavor was rounded out by salt, garlic and cumin. When I had a similar soup at Chase’s Daily the other day, it was served with melted gruyere, which was fabulous.
Sweet potato, leek and celeriac soup
- 3 large sweet potatoes, peeled, and cut in large chunks
- 2 leek stalk, half of the green parts discarded, rest washed and cut into 7 inch parts
- 6 oz celeriac (root), peeled, diced (optional)
- 1/2 TB butter
- 1 shallot, peeled, minced
- 3 garlic cloves, minced
- 1 quart chicken stock (or water)
- 1 cup milk
- 1 TB bouillon
- 1/2 TB cumin
Preheat the oven to 400F. Line a baking sheet with aluminum foil, and place the sweet potatoes and leeks on the baking sheet. Drizzle with olive oil. Bake for 20 min (or leeks slightly charred).
Meanwhile, in a large heavy bottom pot, melt the butter and saute the shallot until translucent. Add the celeriac root and slightly saute. Add the garlic and saute the mix until fragrant. Take off the stove.
Once the sweet potatoes and leeks are roasted, add them to the soup pot. Put back on medium heat, slightly saute, and add the chicken stock, milk, bouillon and cumin. Bring to a boil, and reduce heat to a soft simmer. Simmer for about 20min. With an immersion blender, bring the soup to a smooth consistency.
Add some fresh grated garlic. Serve with grilled bread and melted Grueyere.