01 - Preheat oven to 425°F. Line a large baking sheet with parchment paper.
02 - Peel sweet potatoes and slice into evenly sized fries approximately 3/8 inch thick.
03 - In a large bowl, toss fries with olive oil, smoked paprika, garlic powder, sea salt, black pepper, and cornstarch if using, until evenly coated.
04 - Spread fries in a single layer on the prepared baking sheet, ensuring they do not touch to maximize crispiness.
05 - Roast for 15 minutes, flip fries, then continue roasting for an additional 12 to 15 minutes until golden and crispy at the edges.
06 - While fries roast, combine Greek yogurt or sour cream, mayonnaise, lemon juice, Dijon mustard, minced garlic, chopped herbs, salt, and pepper in a small bowl. Adjust seasoning and chill until serving.
07 - Serve hot roasted sweet potato fries immediately alongside the chilled dip.