Cut pumpkin into chunks and tomatoes in halves. Place them in an oiled baking dish. Drizzle with olive oil, sprinkle with salt and pepper, top with fresh oregano. Roast at 200C for 30-40 minutes. Let cool and remove the skins. In a large pot saute garlic and onion. Add pumpkin and tomatoes, pour in the stock, season with chili and bring to boil. Blend the soup. Check the seasoning and reheat.