Preheat oven to 200°C /180°C fan-forced. Line 2 large baking trays with baking paper. Place pumpkin and garlic in a bowl. Add oil. Season with salt and pepper. Toss to coat.
Arrange pumpkin mixture, in a single layer, on prepared tray. Bake for 40 mi-nutes or until pumpkin is golden and tender.
Squeeze 3 garlic cloves from skin. Reserve. Discard skin. Melt butter in a large saucepan over medium-high heat. Add leek. Cook, stirring, for 3 minutes or until leek has softened. Add potato. Cook, stirring, for 5 minutes.
Add stock and 2 cups cold water. Season with pepper. Cover. Bring to the boil. Reduce heat to medium-low. Simmer for 15 minutes or until potato is tender. Stir in roasted pumpkin and garlic. Cook for 5 minutes or until heated through. Set aside for 5 minutes to cool slightly.
Blend pumpkin mixture, in batches, until smooth. Return to pan over low heat. Cook, stirring, for 2 to 3 minutes or until heated through. Ladle into serving bowls. Add a dollop of natural yogurt and sprinkle with chives. Serve with Gluten free bread.