Ingredients:

  • 2 lb (900 g) sweet potatoes, peeled or scrubbed (choose firm, medium-size)
  • 2 tbsp (16 g) cornstarch (cornflour)
  • 2 tbsp (30 ml) neutral oil (vegetable, canola, or light olive oil)
  • 1 tsp (5 g) fine sea salt, divided (½ tsp in the toss, remaining to finish)
  • 1 tsp (2 g) smoked paprika
  • 1/2 tsp (1.5 g) garlic powder
  • 1/4 tsp (0.5 g) freshly ground black pepper
  • Pinch cayenne or chili flakes (optional)
  • 2 tbsp (8 g) chopped fresh flat-leaf parsley (optional, for garnish)
  • Lemon wedges, for serving (optional)
  • For the Malt-Vinegar Aioli:
  • 1/2 cup (120 g) mayonnaise (use light or vegan mayo if preferred)
  • 1 tbsp (15 ml) malt vinegar (or apple-cider vinegar if unavailable)
  • 1 tsp (5 g) Dijon mustard (optional)
  • 1/4 tsp (1 g) fine sea salt
  • Freshly ground black pepper, to taste

Instructions:

  1. Preheat oven to 450°F (230°C). If using convection, set to 425°F (220°C). Line a rimmed baking sheet with parchment or lightly oil the sheet; place a wire rack inside if using.
  2. Cut sweet potatoes into even 1/2-inch (12 mm) fries for uniform cooking. Optional: place cut fries in cold water and soak 30 minutes to remove surface starch, then drain.
  3. Drain and dry the fries thoroughly with a salad spinner or clean kitchen towels until no surface moisture remains.
  4. In a large bowl toss dried fries with cornstarch until evenly coated. Add oil, ½ tsp salt, smoked paprika, garlic powder, black pepper, and cayenne if using; toss to combine.
  5. Spread fries in a single layer on the prepared sheet, leaving space between pieces to avoid overcrowding; use two sheets if necessary.
  6. Bake on the middle rack for 12–15 minutes until the undersides begin to brown.
  7. Flip fries with tongs or a spatula and continue baking 10–20 minutes until golden-brown and crispy at the edges; for extra crispness, move to a higher rack for the last 3–5 minutes.
  8. Transfer fries to a wire rack or paper-towel–lined plate and rest 2–3 minutes. Immediately sprinkle remaining sea salt and chopped parsley.
  9. While fries bake, whisk together mayonnaise, malt vinegar, Dijon mustard (if using), salt, and pepper in a small bowl until smooth; taste and adjust acidity and seasoning.
  10. Serve fries hot with malt-vinegar aioli and lemon wedges. Optional: provide a small bowl of malt vinegar for splashing, and re-crisp leftovers in a hot oven or air fryer.