Fennel, potato & scallop soup

Ingredients

• 5 fennel bulbs, trimmed, coarsely chopped, fronds reserved
• 2 tablespoons olive oil
• 1 leek, coarsely chopped
• 2 stalks celery, trimmed, coarsely chopped
• 1 swede, coarsely grated
• 2 cloves garlic, crushed
• 1 potato
• 3 cups (750ml) chicken stock
• 2 1/2 cup (625ml) water
• 1 cup (250ml) pouring cream
• 12 (300g) scallops, roe removed
• 40 grams butter
• 1 tablespoon lemon juice
• Caramelised fennel
• 30 grams butter
• 1 fennel bulb, sliced thinly
• 1 tablespoon brown sugar
• 1 tablespoon sherry (optional)