Perfectly roasted sweet potatoes are balanced beautifully by an elegant dressing of cider vinegar, fresh garlic and peppery arugula. Hazelnuts add texture and buttery richness. Due to their high fat content, hazelnuts are particularly susceptible to rancidity. For optimal shelf life, store in an air-tight container in the freezer, for up to 3 months.
Preheat oven to 400 degrees F. Cut sweet potatoes in half lengthwise, then cut in wedges. Place on a large rimmed baking sheet. Toss with oil and season with salt and pepper.
Roast sweet potatoes for 15 minutes. Toss, then roast 15 minutes longer or until tender. Sprinkle with minced garlic and hazelnuts, then return to oven for 4 to 5 minutes, until nuts are toasted and garlic is softened. Remove from oven; sprinkle with arugula and vinegar.