Preheat the oven to 200°C and line a baking sheet with parchment paper.
Use a clean kitchen brush to remove any dirt from the Jerusalem artichokes. Then, rinse them under cold water until perfectly clean. Or peel them if desired.
Cut the vegetable in half or quarters depending on the size (see step-by-step pictures in the post above). Add them to a salad bowl. Generously drizzle with olive oil and sprinkle Italain spices and fresh rosemary (approx. 1 sprig). Swirl around until evenly coated.
Place the Jerusalem artichokes cut side down on the baking sheet. Roast for 45 minutes until golden bornw and small bubbles start appearing.
Remove from the oven and adjust seasoning if necessary. Add some more fresh rosemary and serve.