Halve, core and cut the pumpkin into pieces. Wash tomatoes and cut in half. Peel the onion and cut into rings. Peel the garlic cloves.
Put the vegetables in an ovenproof dish and sprinkle the rosemary sprigs on top. Salt generously and sprinkle with fresh pepper from the mill. Drizzle with olive oil and roast in the preheated oven for about 50 minutes. Then let it cool down and remove the rosemary.
Bring the vegetable stock to the boil. Add the vegetables and purée finely with a hand blender. This creates a creamy, thick soup.
Chop and add olives. Reheat the soup and arrange on plates. Sprinkle with coarsely grated parmesan and serve.