Preheat oven to 250 °. Put olive oil and vegetables in an ovenproof pot / plate. Roast vegetables for 20-25 minutes.
Remove pot from oven and add cream and broth. Put in the oven for another 15 minutes. Remove from the oven and use a hand blender or a regular blender or food processor and puree until smooth. Put in the oven for another 5 minutes and season with salt, pepper and sugar. Remove from the oven and top with Parmesan and olive oil.