My purple sweet potatoes arrived when I had the flu. At the time, I could barely manage eating anything other than an occasional grape, so the potatoes went deep under cover in a dark cupboard waiting for their moment. In truth, I nearly forgot about them. Several weeks later, they were still perfectly lovely and have admirably served their purple potato purpose in this velvety fall soup.
I was a bit skeptical of the recipe at first. The list of ingredients seem like very unlikely friends that I never would have guessed would get along so well - a little like the gang in The Breakfast Club. The secret here is the balance of the slightly sweet soup with the salty roasted mushrooms. The original recipe was vegan which I didn't notice until I was eating it. I'm decidedly not vegan - I will never give up dairy, not even for 24 hours thank you very much. I unintentially un-veganed the recipe by adding a blob of sour cream and I'm not a bit sorry that I did.
Purple Sweet Potato Soup with Salted Mushrooms
adapted from McKel Hill, Bon Apétit December 2016
4 cups mushrooms (portobello worked well), chopped
1/4 cup balsamic vinegar
4 tbsp olive oil
I pound purple sweet potatoes - unpeeled
1/2 onion chopped
1/2 tsp ground cinnamon
1/2 tsp ground cumin
1/4 tsp chili powder
Fresh ground pepper
1 13.5 oz can light coconut milk
13.5 oz filtered water
1/4 cup fresh thyme leaves, reserve 1 tbsp for garnish
Juice of 1 lemon
1 tbsp pure maple syrup
Olive oil to garnish
Preheat the oven to 400ºF. Line two baking sheets with foil. Arrange the sweet potatoes on the first baking sheet and place in the oven and bake in the center of the oven for 40 minutes, or until the natural sugars start to caramelize and they are soft when poked with a knife in the center. At the same time, in a large bowl, combine the mushrooms, vinegar, 2 tablespoons of the oil, and 1 tablespoon salt and stir to combine. Spread the mixture evenly on the second lined baking sheet. Place the mushrooms on the bottom rack when there are 15 minutes left on the sweet potato timer. They should be firm and dry, not crisp.
In a medium skillet, warm the remaining 2 tablespoons oil over medium heat. Add the onion, 1 teaspoon salt, the cinnamon, cumin, chili powder, and pepper to taste and sauté for 5 minutes, or until the onion is fragrant and translucent.
Transfer the onion and baked sweet potatoes to a high-speed blender and add the coconut milk, water, the 1/4 cup thyme, the lemon juice, maple syrup, and salt and pepper to taste. Blend until the soup is thick and creamy. Be sure to have the blender lid on securely before blending. (Alternatively, add the remaining ingredients to a soup pot and blend with an immersion blender.) If you find that it’s too thick (not all potatoes will have the same starch content), thin the soup with water. Adjust seasonings to taste.
Serve the soup in bowls, topped with 2 to 3 tablespoons of the mushrooms, a sprinkling of thyme, and a drizzle of olive oil. Serve hot/warm. Store in an airtight glass container in the refrigerator for up to 1 week.