01 - Set oven to 425°F and line a large baking sheet with parchment paper.
02 - Peel and cut sweet potatoes 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 thoroughly coated.
04 - Spread fries in a single layer on the prepared baking sheet, ensuring they do not touch to promote crispness.
05 - Bake for 15 minutes, flip fries, then continue roasting for 12 to 15 minutes until edges are golden and crisp.
06 - 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 fries hot alongside the chilled dip.