Can I just say it? This soup is fabulous.
It’s perfect for early fall, when foggy mornings give way to sun-warmed afternoons, and the evenings are deliciously cool. Not too heavy or hearty, but layered with autumnal flavors.
I’d also like to say that takes only a few minutes on the stove, but that wouldn’t be exactly true. There’s the little matter of the roasted pepper purees…
Right now, freshly dug sweet potatoes have taken over our farmers’ market. Rosy-skinned Covingtons, purplish Garnets, old-time Beauregards. They’re all nice, but this early in the season they’re also a little bland. The luscious flavor comes later, after they’ve had a good, long cure. Not the standard week to 10 days in “a warm, well-ventilated room,” but a month or two in a dark pantry, in which their natural sugars have time to develop the gorgeous, caramelized taste that makes them so irresistible after a turn in the oven.
In our hyped-up times, it can be hard to make a case for delay, but sometimes waiting pays off. As in waiting to get married until I was in my thirties (oh, the misery I’d have caused if I’d succumbed a minute earlier), waiting for babies (so much more patience when you’re in your prime), even waiting fourteen years for a new garden come into full and glorious bloom.
Timing is everything. It’s not just about the joy you feel when your dream is finally at hand. It’s about what happens along the way, as you grow and change, and maybe even slow down. The kitchen analogy might be the glorious chemistry that takes place in the pot—or tagine—during a slow braise.
But back to those sweet potatoes. Even if they haven’t had the benefit of a long cure, young sweet potatoes have certain virtues: They’re fresh-tasting and tender, and they present a nearly blank canvas that can be painted with bright spices and other seasonings.
This soup is a case in point.
I began with warm Ceylon cinnamon, a natural for sweet potatoes, since its own sweetness brought out the potatoes’ honeyed flavor, while its astringency kept the soup from becoming cloying. But then I veered off in other directions, adding bitter lime zest and tangy juice to brighten the mixture, and allspice, the orphan of the spice cabinet, for complexity.
Allspice has an odd, checkered history. It was first discovered, some say, on the island of Jamaica by Columbus, who mistook the islands of the Caribbean for the East Indies. Later Spanish explorers confused the berries, which come from the evergreen pimento tree, with peppercorns, but it was not until 1601 that the spice was shipped to Europe—as a substitute for cardamom. Almost a century later, in 1693, an English botanist named the aromatic brown berries “allspice” because they were said to taste of cinnamon, nutmeg and clove. (You can find this info and much more in Maggie Stuckey’s Complete Spice Book.)
But does allspice really taste that way? In Spices, Salts and Aromatics in the English Kitchen, Elizabeth David said decisively, “I myself cannot see where the nutmeg or cinnamon come in. A hint of clove is certainly there, and more than a hint of pepper.”
That comment led me to try it in the sweet potato soup, which at this point still needed “something.” But when I crushed the allspice—the outer shell mingling with the hidden seeds—a third flavor emerged: the cool, aromatic taste of the juniper berry. It was almost like adding a splash of gin to the mix.
To finish, I stirred in two kinds of pureed peppers. One, made of fire-roasted sweet red and yellow peppers, riffs on the smoky green chilies that waft their delectable aroma through the fall Saturday market. For the other, I blended the dried smoked Oaxaca pasilla chiles I found at Spice Ace with roasted tomato, onion and a little olive oil.
Swirled into the bowl just before serving, they added the finishing touch to a seasonal soup filled with tantalizing flavors.
And yes, it’s a soup worth waiting for.
Sweet Potato Soup with Smoked Pasilla Peppers, Lime Zest and Allspice
If you cannot find smoked Oaxaca pasilla chiles, try substituting standard dried pasilla peppers and seasoning them with any smoked salt. Standard pasillas are available in Hispanic markets, in the international section of many supermarkets, or from MexGrocer. Smoked Oaxaca pasillas, and for that matter, smoked salts, can be ordered from Spice Ace.
To serve four people.
2-3 tablespoons olive oil
¾ cup celery, thinly sliced
1-1/2 cups onion, thinly sliced
2-1/4 pounds sweet potatoes, peeled, quartered and thinly sliced
1 tablespoon garlic, chopped
1-inch piece Ceylon cinnamon
1 scant tablespoon allspice, lightly crushed
4 cups chicken broth
1 cup dry white wine
Sea salt and freshly ground black pepper to taste
Zest of one lime
1 tablespoon lime juice, or to taste
Smoked pasilla pepper puree (recipe follows)
Roasted sweet pepper puree (recipe follows)
Cilantro, finely chopped, as a garnish
Roasted peanuts, coarsely chopped, as a garnish
1. In a large saucepan, heat the olive oil over a medium flame. Add the celery and onion, and gently saute, stirring often, until soft. Add the garlic and sweet potato and continue cooking until the sweet potatoes are fairly tender. Do not let the vegetables brown. Reduce the heat if necessary.
2. Stir the cinnamon and crushed allspice into the vegetables and continue to cook for 1 to 2 minutes until their fragrance is released
3. Add the chicken broth and white wine. Bring to a boil, then reduce the heat to medium low. Maintain a brisk simmer for 15 minutes or until the potatoes are tender. Remove from the heat and let cool for 5 to 10 minutes.
4. Pour the soup into a high-speed blender or food processor and puree until very smooth. Do this in batches if necessary.
5. When all the soup is pureed, pour it back into the pan. Stir in the lime zest and lime juice, as desired. Taste for seasonings, adding sea salt and pepper as needed.
6. When ready to serve, warm the soup gently over low heat. Pour it into individual soup bowls and swirl the two pepper purees over the surface of the soup. Sprinkle with finely chopped cilantro and chopped peanuts, and serve at once.
Smoked Oaxaca Pasilla Chile Puree
4 large dried pasilla peppers, preferably smoked from Oaxaca, or 4 plain dried pasilla peppers
1 large onion, peeled and cut into quarters
1 medium ripe tomato
Sea salt, or substitute smoked salt if needed
1. Heat a comal or cast iron frying pan over a medium flame. When the pan is hot, add the dried pasilla peppers. Turn them frequently with tongs, until the surface of the skin is blistered and puffed, and the color has turned medium brown. Immediately remove to a plate. Do not let them burn.
2. Cover the peppers with boiling water and soak for 10-15 minutes until they are soft. Remove the seeds and stems.
3. While the peppers are soaking, char the quartered onion in the same cast iron pan or comal and set aside. Do the same with the tomato, turning it frequently so that all sides are charred. Peel and set aside to cool.
4. Combine the softened peppers, onion and tomato in a high-speed blender or food processor and puree until very smooth.
5. Pour into a small bowl. Stir in a little olive oil and add salt to taste. (Substitute smoked salt if you’re making the puree using standard dried pasillas.) Set aside.
Roasted Sweet Pepper Puree
To roast 1 pound of mixed red and yellow Bell, Corno di Toro or other sweet peppers, follow the directions here.
After roasting the peppers, remove the skin, and discard the seeds, then puree the peppers in a blender until smooth. Pour into a small bowl and set aside.