Pity the poor sweet potato fry.
Too often it's a soggy, limp cousin to its white-potato kin, never reaching the expected crispness we've been conditioned to expect from a fry.
In large part, that's because most sweet potato fries commonly available in restaurants are prepared in the same way as regular fries — a brief bath in a deep fryer — which usually dooms them to a short unhappy life, pushed away to the edge of a plate.
Crispy sweet potato fries actually can be made at home, which I tried more than a dozen times recently. At the holidays, some families like their sweet potatoes mashed and buttery and covered with marshmallows. Others spread them into a pie or whip them into a souffle with eggs and spices. But cutting the potatoes into strips and roasting in a light film of oil is a healthy approach for the holiday table and helps unleash the potatoes' flavor. The best and least oily were coated with canola oil and spices and roasted in a hot oven, which yields great fries if you exercise some patience and diligence in the last 10 minutes. That final roasting time is when the magic happens, when the soluble sugars of the potato undergo complex physical and chemical changes that give each fry a delicious browned crust.
Of course, roasting isn't the only way to go. With proper oil temperature control, it's possible to deep fry sweet potatoes to an acceptable level of crispness. Adding the strips of potato in small batches will keep them from sticking together in a gloppy mess and result in nicely browned fries with soft centers. But the crispness clock immediately starts ticking the instant the fries are removed from the hot oil because the sweet potato's higher moisture will migrate to the crisp exterior, turning them soggy within minutes.
Blasting the fries with dry heat takes advantage of the complex Maillard reactions that occur during roasting, and helps retain the sweet potato's natural nutritional advantages. Ounce for ounce, sweet potatoes are among the most nutritious vegetables available, but they're most commonly served drowned in butter and sugar — or deep fried. Oven-roasted fries are a guilt-free alternative.
Choosing the right sweet potatoes is important. White sweet potatoes can be used, but they're often long, lean and fibrous. Stick to jewel or garnet varieties, which often are mistakenly labeled as yams. Gnarled, scrawny ones are sweet but often stringy. Large ones can contain excess moisture and not much flavor. A medium sweet potato is about the size of a large russet potato, and often will be sweeter than the football-shaped ones, but not as fibrous as the runts of the bin.
Peeling the sweet potato is optional, but the skins add texture and crunch. Most important is cutting the potato into relatively uniform slices, about 1/2-inch thick, which makes the task of timing the exit a bit easier. Wedges are fine, but it's better to square off the extreme angles to prevent them from burning before the rest of the slice is cooked through.
Before roasting, season the fries lightly with salt, pepper and paprika. Old Bay seasoning can be added instead of salt. In our house, we use dry Indian rogan josh seasoning (penzeys.com) for a deeper, more complex flavor. Most blends are a mixture of spices such as paprika, ginger, cumin, cayenne, cinnamon and cloves, most of which are featured in other holiday dishes.
Spicy Oven-Roasted Sweet Potato Fries
2 tablespoons canola oil
1 teaspoon dry rogan josh seasoning or 1/2 teaspoon of rogan josh paste
3 medium sweet potatoes
Salt and pepper, to taste
Set the oven at 400 degrees (use regular or convection setting). Have on hand 2 large rimmed baking sheets.
In a large bowl, combine the oil and seasoning or paste. Mix with a fork or whisk to release the flavor and color.
Wash the potatoes thoroughly if you're leaving the skin on; pat dry with paper towels. Slice potatoes lengthwise into wedges or thick rectangular sticks, about 1/2-inch thick. In batches, add potatoes to the bowl and use your hands to toss the potatoes with the oil and seasoning until they are thoroughly coated.
Arrange a layer of potatoes on the baking sheet, leaving about 1/4 inch between the slices. Do not crowd the pan. Transfer to the oven and roast for 15 minutes. There should be a thin layer of liquid accumulating at one corner of the pan. Turn the fries, coating each fry in the sugary pan juices. Continue roasting another 15 minutes, watching the fries extremely closely for the last 10 minutes. Remove them when the edges are golden brown and the fries are tender when pierced with a skewer. Sprinkle with salt and pepper if needed.