Prawns with a Bisque and Tomato Fregola

Ingredients

• 500g raw tiger prawns, in their shells
• 120ml olive oil
• 2 banana shallots, diced
• 6 plum tomatoes, diced
• ½ fennel bulb, diced
• 2 sprigs of rosemary, needles picked
• 2 garlic cloves, sliced
• 1 tsp coriander seeds
• 1 tsp fennel seeds
• 1 tbsp tomato purée
• 4 tbsp tomato ketchup
• 100ml white wine
• 1 litre tomato juice
• 1 litre good-quality fish stock
• 500g fregola
• 50-100g crème fraîche
• sea salt
• freshly ground black pepper
• ½ bunch of tarragon, leaves chopped
• extra virgin olive oil, for drizzling