Spiced Carrot Soup with Parmesan Crisps

Ingredients

• 20 g butter
• 1 large (200g) onion, chopped
• 1 celery stick, sliced
• 1 teaspoon ground cumin
• 1/2 teaspoon ground coriander
• 1 kg carrots, chopped
• 1 litre (4 cups) vegetable stock
• 4 multi-grain tortillas
• 2 tablespoons extra-virgin olive oil
• 1 teaspoon sweet paprika
• 1/2 cup (40g) finely grated Parmigiano Reggiano PDO
• 2 tablespoons light sour cream
• Coriander leaves to serve