Preheat oven to 180°C. Place pumpkin, ginger and garlic on a large baking tray and drizzle with oil. Season, then toss to coat. Roast for 30 minutes or until the pumpkin is soft (don’t let the garlic burn).
Puree mixture in a blender or food processor with 2 cups (500ml) stock, then season. If there are lumps, strain through a fine sieve. Place soup a large saucepan with remaining 2 cups (500ml) stock and warm over medium-low heat.
Divide soup among 4 bowls, top with mascarpone and serve with dill and nuts.
