Contributed by Megan Saynisch, from the Real Food Right Now series.
You will need about 2 1⁄2 cups of cooked sweet potatoes for this recipe — perfect for using up leftover sweet potatoes. Before a big meal, I like to serve creamy, filling soups like this in teacups so my guests don’t fill up before the main event. Or serve the soup as a main course with a green salad and crusty bread or biscuits. If you want to be really fancy, it’s pretty easy (and much cheaper) to make your own crème fraîche (seriously!). You could also substitute plain yogurt for the crème fraîche.
1 tbsp extra virgin olive oil
1 tbsp unsalted butter
1 med yellow onion, diced
1 small, tart apple (like Granny Smith), peeled, cored and diced
1 carrot, peeled and diced
1 celery stalk, diced
8-10 small sage leaves
3 cups chicken or vegetable stock
2 1⁄2 cups peeled, cooked sweet potatoes, from about 1 large, mashed or diced (see note)
1⁄4 teaspoon cayenne pepper
1⁄4 teaspoon freshly ground nutmeg
Juice of half a lemon
1⁄4 cup crème fraîche or plain yogurt
In a medium Dutch oven, heat the extra virgin olive oil and butter on medium-high heat until the butter is just melted. Add the onion, and cook and stir until translucent (but not browned), about 5 minutes.
Add the diced apple, carrot, celery and sage and cook and stir for another 2-3 minutes.
Add the chicken or vegetable stock. Bring the mixture to a gentle boil, then turn the heat to low. Simmer until the carrots and celery are tender, about 15 minutes.
Add the cooked sweet potatoes, cayenne and a grating of nutmeg. Stir to combine. At this point, taste for salt – depending on the saltiness of your chicken or veggie stock, you will have to adjust the seasoning. Simmer for 2-3 minutes to allow the flavors to meld.
Purée the soup in batches in a blender (take care with hot liquids!) or food processor. (Or use a stick blender, my kitchen BFF.)
Stir in the lemon juice to taste. Taste and adjust for salt again.
To serve: swirl a dollop of crème fraîche or yogurt on top of the soup. Serve hot.
Serves 3-4 as a main course.
Note: Starchier sweet potatoes, like Japanese sweet potatoes, will produce a soup more like a traditional potato soup. Sweeter, moister sweet potatoes, like the orange-fleshed Jewels, will make a sweeter, more sweet potato-y soup. You can also cook the sweet potatoes directly in the soup, rather than use cooked sweet potatoes: just add the uncooked sweet potatoes before you add the stock, and adjust the timing accordingly (sweet potatoes will take a little longer than carrots to become tender).
Learn more about sweet potatoes in Megan’s full post on Ecocentric Blog.