Heat some olive oil in a saucepan over medium heat and sauté prawn heads and shells for about 5 minutes on high. Once nicely browned add the celery, onion, fennel and cook until start to soften. Add garlic then tomato paste and cook for a further 2 minutes, deglaze with white wine. Then add enough water to cover about 1lt. bring to boil and simmer for 1 hour. Once finished turn off the heat and leave to cool slightly. Strain and set aside.
Meanwhile, cook the pasta according to the packet’s instructions.
To make the pasta heat remaining olive oil in a fry pan and lightly sauté the garlic and tomatoes. Add the prawns and sauté until lightly coloured, for about 2 minutes, then add 300ml stock and reduce by half. Gently fold the pasta through, add the basil, parsley and a little olive oil to finish.