Spiced parsnip and apple soup

Method

1. Heat a small, dry frying pan over a medium-high heat. Add the cumin, coriander and cardamom seeds and shake them around for a few seconds until they toast and darken slightly. Tip into a spice grinder or pestle and mortar (or a coffee grinder used only for spices) and grind to a fine powder.
2. Heat the butter and oil in a medium-size pan. Add the onion, cover and cook gently for 10 minutes until soft and lightly golden. Meanwhile, peel the parsnips and cut them into 2.5cm pieces.
3. Uncover the pan, add the garlic, grated ginger and all the spices, then cook for 1 minute more. Add the parsnips, chopped apple and stock, then bring to the boil, cover and simmer for 45 minutes to 1 hour until the parsnips are really tender when you test them with a knife.
4. Remove soup from the heat and leave to cool slightly, then liquidise until smooth. Pour it through a sieve into a clean pan, using a wooden spoon to push it through. Season to taste.
5. To serve, stir in the crème fraîche. Serve in warm bowls, garnished with a little more crème fraîche and chopped chives.