Starchy vegetables have a long history of being used to make tasty and nutritious soups. Potatoes, pumpkin, butternut squash, zucchini, peas, and beets are the main ingredients in soups around the world. One of the most overlooked starchy vegetables is the sweet potato, which is a shame because it’s packed with flavor and goodness.
To be clear, I’m talking about the sweet potato which is also sometimes referred to as “yams”. True yams are not often found in North America, but confusion arises because there are two common varieties of sweet potato. First, there is a harder variety with a yellow interior and a softer orange type. The orange ones that are sometimes called yams are my favorite, and they are the best to use in this soup.
Sweet potatoes have a much more complex mix of starches and sugars, so they benefit greatly from the caramelization that takes place in the roasting process. Its natural sweetness intensifies and the overall flavor becomes richer. If it looks like you’re going to turn this recipe into a dessert, don’t be fooled: even savory flavors improve when toasted.
To start making this soup, preheat your oven to 400 degrees Fahrenheit. Clean two or three large sweet potatoes and poke holes in them with a steak knife or something similar. (Do not peel.) Place the sweet potatoes in a baking dish and roast for about an hour. They will be soft to the touch when ready and will likely drip an orange liquid. Let them cool, then remove the skin (they will come off very easily if they are done). You can roast the sweet potatoes ahead of time and use them later, or you can start the next process when you take them out of the oven.
The next step is to thinly slice a large onion. Heat a small amount of butter and olive oil in the soup pot and add the onion and a little salt. Slowly cook the onions until golden brown, but do not allow them to burn. The darker the onions get, the more they caramelize, just like sweet potatoes. This will really bring out the flavor of the soup. (Note: if you like, you can add a few cloves of garlic for even more flavor.)
Chop the cooked sweet potatoes and add them to the pot. Mash them up a bit, then add about 4 cups of chicken broth or whatever broth you prefer. Bring the soup to a boil, then reduce and cook until it reaches a desirable consistency. Use an immersion blender to puree the soup. Add up to half a cup of heavy cream and a dash of nutmeg, and voila!
Here are the ingredients listed again for convenience:
2-3 large sweet potatoes;
1 large onion;
1-4 cloves of garlic (if desired);
butter and/or olive oil;
4 cups of chicken broth or some kind of broth;
half a cup of heavy cream;
nutmeg (or try some allspice and cayenne pepper for a spicy version)
I hope you enjoy this recipe as much as I do!