Preheat oven to 425 degrees. Line a baking sheet with a piece of parchment paper.
Slice sweet potatoes into long quarter inch thick sticks (roughly). Keeping in mind that uniform cuts results in equal roasting. Slicing them thicker than 1/4 inch will result in softer fries (not crispy).
Add cut sweet potatoes to a large mixing bowl. Sprinkle sea salt, black pepper, garlic powder and arrowroot starch (or cornstarch) over potatoes.
Toss the seasonings with potatoes and massage until evenly coated.
Drizzle olive oil on top of the potatoes and toss to coat once more. Be sure to pick up as much of the seasonings as possible with the oil.
Place each sweet potato fry onto the prepared baking sheet. Arrange potatoes in a single layer, without touching. This is key to get the best crisp.
Bake sweet potatoes for 18 minutes. Flip each fry, and then bake for an additional 10-12 minutes. Potatoes will be crisped and browned around the edges when done; watch closely around the 10-minute mark as all ovens vary. Remove from oven and allow to cool on baking sheet. Fries will continue to crisp as they cool.
While sweet potatoes are cooking, prepare the garlic aioli sauce.
Mince garlic and add to a small bowl.
Add mayonnaise, lemon juice, kosher salt and dijon mustard to the garlic. Stir until ingredients are combined. Drizzle with olive oil over top.
Serve fries alongside garlic aioli dipping sauce.
Notes
Tips for Success
Cut the fries evenly for consistent cooking.
Don’t overcrowd the pan or the fries may steam instead of crisp.
Use arrowroot starch or cornstarch for the best texture.
Let the fries cool slightly after baking so they continue crisping up.
How to Store
Sweet potato fries are best enjoyed fresh, but leftovers can be stored in an airtight container in the refrigerator for up to 5 days.
To reheat, place them in a 350°F oven for 10–15 minutes or warm them in an air fryer until heated through. The microwave works as well, but the fries will be softer.
Store the garlic aioli separately in the refrigerator.