OK, let’s get the confusing part over with. Those sweet, moist, typically orange roots we eat at Thanksgiving are sweet potatoes (Ipomoea batatas), not yams. A yam is something completely different. True yams (Dioscorea batatas), which are hard to find in grocery stores, are very starchy and dry. They have thick skins and white flesh and look like knotty roots. If you saw or tasted one, you wouldn’t mistake it for a sweet potato.
Now that we have that cleared up, the rest of the sweet potato story is pretty straightforward. Highly nutritious (they’re rich in beta carotene, vitamin C, and good carbohydrates), sweet potatoes have thin, edible skins and come in many shapes and colors, from the more common orangefleshed varieties to yellow- and even purple-fleshed ones. The deep-orange sweet potatoes are usually moister and sweeter than their yellow counterparts. I’m partial to a variety called Garnet, which has very dark flesh that’s especially sweet and creamy. Sweet potatoes come into season in late summer and are available right through spring, but they’re at their best in the fall and early winter.
At the market, choose firm, unblemished sweet potatoes and handle them with care, as they bruise easily. I am mystified by the admonition to use sweet potatoes soon after buying, because stored in a dark, cool place with good air circulation, they’ll keep for months. They will get drier, but they’re still perfectly good.
Bake sweet potatoes today, use them tomorrow
Baked sweet potatoes keep well in the fridge for a week or longer, so you can have them on hand to mash or use as twice-baked, in a soup, or just warmed up whole and brightened with a knob of herb butter or a spoonful of pesto.
Try different flavor partners
I like to liven things up by adding something pungent, spicy, sour, or salty to play counterpoint to sweet potatoes’ sweetness. Sharp cheeses pair well, as do sour cream, crème fraîche, and yogurt. Toasted pecans or walnuts are wonderful, as are sautéed or caramelized onions or shallots and roasted garlic. I find that all fresh herbs make good flavor partners, and citrus juice and zest of any kind add sparkle. Among condiments and spices, I like soy and ponzu sauces, balsamic vinegar, maple syrup, curry powder, ginger, and paprika (especially the smoked Spanish type, pimentón).
Sweet potatoes are easy to prep. All you need to do is peel and cut them—and sometimes neither is necessary. They’re good baked, fried, sautéed, and even boiled. They’re a flavorful addition to winter braises and if you dice and roast them, they make a quick and tasty side to any fall dish. One of the best methods for cooking sweet potatoes is to bake them whole in their jackets. I don’t even oil the skins (which, incidentally, I enjoy eating). I just lay them on a baking sheet and put them in a 425°F oven for about an hour, until they’re very tender. A pat of plain or flavored butter is all they need—or a spoonful of pan juices if you’ve roasted some meat.
Prep sweet potatoes ahead
As with any potato, peeled sweet potatoes will darken when exposed to air. To prevent this, keep cut potatoes fully submerged in a bowl of cold water until ready to cook, then pat dry and proceed with your recipe.
Sweet potatoes any way you want them
- Make rich twice-baked sweet potatoes using leftover baked sweet potatoes. Cut the potatoes in half lengthwise and scoop out the soft flesh. Mash it and mix with softened shallots, grated Asiago, crisp bacon pieces, and a dollop of crème fraîche. Refill the empty skins and bake in a 375°F oven until hot and toasty on top, 45 minutes to 1 hour.
- Put together an early fall soup of sweet potatoes, caramelized onions, red peppers, and fennel or corn. Caramelize the onions in olive oil, then add the red pepper, sweet potatoes, and fennel or corn and lightly brown them. Season with salt and pepper, add vegetable broth, and simmer until very tender. Purée the soup, enrich it with a bit of cream, and garnish with fennel fronds or chopped parsley.
- Try sophisticated sweet-potato fries. Cut peeled sweet potatoes (a very large one will serve two) into 2×1/4-inch matchsticks. Heat a little oil in a heavy sauté pan, add the sweet potato sticks, and sauté over medium-high heat, tossing frequently until browned and tender, 12 to 15 minutes. Season with salt, a dash of cayenne, lime juice, and chopped cilantro.
- For tasty sweet-potato mashes, mash boiled or roasted sweet potatoes with orange juice, ginger, and cream or with toasted and ground coriander seed, a little sour cream, and cream.
- Make a simple Thai-style curry by cooking chunks of peeled sweet potatoes and russet potatoes, onion slices, and diced bell pepper in curry paste and vegetable oil for a few minutes. Pour in coconut milk, add a wild lime (kaffir) leaf, and simmer until vegetables are tender. Season with salt and pepper and serve with rice.
- Make crispy-tender roasted sweet potatoes. Toss peeled and diced sweet potatoes with olive oil, chopped rosemary, chopped thyme, salt, and pepper and roast in a 450°F oven until browned on the outside and tender inside, about 20 minutes. Sprinkle with fresh lemon zest before serving.