First Step: Preheat and prepare sweet potatoes

Preheat the oven to 180°C (350°F). Wash sweet potatoes thoroughly and either peel or leave the skin on based on preference. Using a mandoline or sharp knife, slice sweet potatoes into uniform 3-4 mm thick rounds to ensure even cooking and facilitate the spiral arrangement.

Second Step: Coat and season slices

Place the sweet potato slices in a large bowl. Drizzle with melted butter and 2 tablespoons of olive oil. Add minced garlic, chopped herbs, salt, black pepper, and the optional grated Parmesan or similar hard cheese. Gently toss to evenly coat each slice, taking care to keep slices separated for even roasting.

Third Step: Arrange in a spiral pattern

Lightly oil an ovenproof skillet or baking dish with olive oil or use oil spray. Starting at the perimeter, arrange the sweet potato slices in a circular spiral, slightly overlapping each piece, working your way toward the center to create a visually striking pattern. For square or rectangular dishes, lay slices in neatly overlapped rows.

Fourth Step: Initial baking

Cover the dish with aluminum foil to prevent drying and bake for 30 minutes. This pre-cooks the sweet potatoes partially, ensuring tenderness while maintaining firmness for the final bake.

Fifth Step: Finish caramelizing

Remove the foil and increase the oven temperature to 210-220°C (410-430°F). Brush or lightly spray the top with the remaining olive oil. Bake uncovered for an additional 20 minutes, or until the edges caramelize to a golden, chewy texture and the potatoes are fully cooked when tested with a fork or knife.

Final Step: Garnish and serve

Remove from oven and garnish with extra fresh herb sprigs and optional sea salt flakes for an added burst of flavor and presentation. Serve immediately to enjoy crisp edges and tender centers, as the caramelized slices soften upon cooling.