Derek's sweet potato and rosemary fries

Preheat the oven to gas 5, 190°C, fan 170°C. Line a large baking tray with nonstick baking paper. Cut the sweet potatoes into long, finger-width wedges and put on the tray. Drizzle with the oil and scatter over the rosemary and garlic powder and season with black pepper. Toss together. Cook in the oven for 25-30 minutes on the top shelf, until lightly golden and soft enough to be pierced through with a fork or skewer. Serve immediately with the rosemary sprigs and your preferred dipping sauce.