Curried Parsnip and Apple Soup

Ingredients

• 2 tablespoons olive oil
• 1 onion, chopped
• 1 pound 5 ounces (600g) parsnips, peeled and chopped
• 2 medium potatoes, peeled and chopped
• 2 garlic cloves, crushed
• 1½ teaspoons curry powder
• 1½ teaspoons ground coriander
• 1 teaspoon ground ginger
• Kosher salt and freshly ground black pepper
• 1 cooking apple, such as a Bramley—peeled, cored and chopped
• 4 cups (1L) chicken stock
• Juice of ½ lemon
• Crème fraîche and crushed toasted coriander seeds, to serve