Two things came together for this soup. First, we picked up more sweet potatoes from the CSA this week, bringing our total to six. That might not seem like very many, but, for two people, six largish potatoes are a bit much, especially given the other produce we have to eat this week; we try to eat almost everything from our CSA share on a weekly basis. Why have fresh food that you don’t eat fresh? The second thing is a bit more mundane. We happened to have Ellen Brown’s book Soup of the Day, on hand, and, when we thought of the sweet potatoes, we also wondered, is there a sweet potato soup that sounds interesting and different that we can make?
There was, Moroccan Sweet Potato Soup. Now, we have no idea if this is a traditional Moroccan soup or not, but we’ll just assume that it is. But we will say that we changed the recipe just slightly, including a secret ingredient most home cooks don’t use, but should.
No, the secret ingredient is not harissa, which is a spicy red pepper paste from North Africa. If you can’t find it, you can learn how we scratch out our own version of harissa. The secret ingredient is vinegar. Everyone knows to season with salt and pepper, but not too many people know to season with vinegar. Yes, season with vinegar. Almost all dishes — maybe not ice cream — are improved with a bit of vinegar to brighten up and bring out flavor. It’s a trick that all chefs use. So, yes, start breaking out that bottle of vinegar when you’re scratchin. Finally, we didn’t use a shallot for our soup: instead, we used some I’itoi onions that we had on hand; they have a nice shallot-like flavor.
Procedure in detail:
Make stock. Easier than you might imagine. You can either use our recipe for roasted vegetable stock, or you can do as we do most of the time and save your vegetable scraps for a week, simmer them in water for 45 minutes, and strain. Either way, freshly-scratched stock is a better choice, and tastier, than buying stock at the store.
Preheat oven to 400°F. Line a baking sheet with a piece of parchment if you want easy cleanup.
Toss vegetables. Place the chunks of potatoes in a medium bowl along with the shallots. Drizzle with the olive oil and sprinkle with salt. Give everything a good tossing to coat. Spread them out on the prepared baking sheet.
Roast vegetables. Place the sheet of vegetables in the oven and roast until the corners of the sweet potatoes start to brown and the shallot and potatoes are soft, about 30 minutes. We would err on going longer to increase the roasted flavor.
Simmer soup. Place the honey, harissa, roasted vegetables, and stock in a large kettle over medium-high heat and bring to a boil. Reduce the heat and simmer the soup until the potatoes are very soft. Just about falling apart soft. This should take 20 to 30 minutes.
Purée. Working in batches, if necessary, purée the soup in a blender until smooth. Super smooth is the texture you want, so let that blender do the work. And, don’t forget, blending hot liquids can cause the lid of a blender to shoot off, spraying everything with boiling hot liquid, so be careful. Once puréed, return to the kettle and warm as needed.
Season. Taste, add the secret ingredient, the vinegar, and taste again. See. See. It does make a difference, right? If needed, add more vinegar, though not too much, as you don’t want to taste it, but just the increase in flavor that comes with the added acid. Add the salt and pepper in the same way, tasting after each addition. Continue warming the soup, if needed.
Serve. Ladle into bowls, and, since this is a spicy soup, a dollop of sour cream will do wonders by adding a cooling note to tame some of the harissa. If you wish, you can garnish with a sprinkle of some mild green herb; we used a bit of dried chervil. Fresh would’ve been better, but we have dried.
First, anytime you see harissa in the ingredients list, you know you’ll have something spicy and hot. But, that’s not what you taste at first. Instead of heat, this soup has a nice, sweet flavor. Not too sweet, but a subtle sweetness from the potatoes and the honey; after that, you get hit with the chili pepper spiciness of the harissa. We were glad we had sour cream on hand to have with the soup. While not our favorite soup, it’s pretty easy to make, so we’ll say four stars.