It’s been a rainy and raw first week of May in New York — pretty much to be expected after a dry, sunny, and warmer-than-usual April. And though not much fun for the humans of nyc (or our canine friends — hello, sink bath after every single park walk!), the trees, lawns, and gardens are loving it, growing more lush and green by the day.
Fittingly, my soup pot has been in heavy rotation the last few days. My favorite spoonable creation as of late is this velvety, gingery, and earthy roasted sweet potato soup. With just 6 basic ingredients — sweet potato, onion, garlic, ginger, turmeric, and coriander seed (homemade broth doesn’t hurt, either; more on that below) — this soup is ultra simple to make yet bursting with flavor, nutrient-density, and sunshine-in-a-bowl satisfaction.
Last Sunday I picked up about a pound each of pastured chicken wings and feet (my favorite parts for making bone broth) from Yellow Bell Farm at the 79th Street greenmarket. I decided to make a small batch — about 1-1/2 quarts — to enjoy during the week as a sipping broth, egg-poaching liquid, and base for soups. Simmered over very low heat for about 8 hours with a splash of apple cider vinegar, a halved onion, a few garlic cloves and a couple of pieces of kombu, with a bunch of parsley stems added for the last 10 minutes, the result was a delicious, rich and mellow broth so rich in gelatin that it turns completely solid once it’s chilled.
(yup, definitely passes the upside-down test)
I also picked up a couple of sweet potatoes at the greenmarket, and with fresh ginger and turmeric on hand, too, decided a sweet potato soup was in order. If you’ve never tried whole-roasting your sweet potatoes before adding them to soup, you must give it a go next time. Cooking the sweet potato in its skin steams the interior of the potato for a super creamy and luscious texture, and draws out just enough of its moisture to concentrate the flavors in a way that doesn’t happen when these sweet roots are cubed and cooked in liquid.
We’re talking a soup that’s super creamy yet entirely dairy-free and gluten-free. Blended with hot broth and aromatics, the roasted sweet potato’s starches create a velvety texture without any need to add butter, cream, or flour. (And it’s easy to veganize — simply use veg broth in place of bone broth.)
For garnishes I chose black sesame seeds, thinly sliced scallions and edible flowers (violets), and I love the way the colors pop against the bright orange of the soup. Toasted pumpkin or sunflower seeds, sliced almonds, a dollop of yogurt or coconut cream, chives, and/or sprouts would also be great finishing touches. If you have a cup or two of leftover soup, try simmering it for 5 minutes with a couple of handfuls of thinly sliced dark leafy greens (kale, mustard greens, chard, collards etc) tossed in. Delicious!
Roasted sweet potato soup with ginger, turmeric and coriander
As noted above, for a vegan soup simply substitute vegetable broth (preferably homemade) for the bone broth.
2 medium sweet potatoes (about 1 pound), scrubbed
1 teaspoon + 1 tablespoon coconut oil, divided
1 medium onion, chopped (about 1 cup)
1 garlic clove, peeled and minced
1-inch piece fresh ginger, peeled and chopped
1-inch piece fresh turmeric, peeled and chopped (or 1/2 teaspoon ground turmeric)
1/2 teaspoon ground coriander seed
3 to 4 cups bone broth or stock of your choice
thinly sliced scallions or chives
Preheat oven to 400F. Line a rimmed baking sheet with parchment.
Rub sweet potatoes with 1 teaspoon coconut oil and sprinkle generously with kosher salt. Place on baking sheet and roast until soft, about 45 minutes. Remove from oven and allow to cool. Remove skins (they should peel off easily).
Heat 1 tablespoon coconut oil in a medium soup pot over medium heat. Add onion and cook for 5 minutes until softened. Add garlic, ginger and turmeric and cook for 1 minute more, stirring often. Add coriander and toast for about 30 seconds more.
Add 3 cups broth to soup pot along with a pinch of salt, and stir to release any bits stuck to the bottom. Simmer on low for 10 minutes, partially covered. Let cool for a few minutes.
Transfer broth mixture (including aromatics) and roasted, peeled sweet potatoes to a blender. Process until mixture is completely smooth, keeping in mind the usual precautions when blending hot liquids in order to avoid a blender volcano: do not fill your blender more halfway (if your blender is small blend your soup in 2 or 3 batches), cover with blender lid and then cover lid with a kitchen towel, and apply pressure to the lid/towel combo while the machine is running.
The consistency of the soup should be thick and creamy but pourable (if it looks like mashed sweet potatoes it’s too thick). Add more broth, about 1/4 cup at a time, if needed to thin it out. Blend after each addition.
Transfer soup back to rinsed pot and reheat over low heat. Season to taste with salt. When ready to serve, ladle into warmed soup bowls and add garnishes of your choice.