For the stock: thoroughly clean the shellfish. Peel and finely dice the shallots.
Heat a saucepan to hot and add a drizzle of olive oil. Add the shallots to the pan and season with a pinch of salt. Cook for 1 minute and then add the shellfish and the white wine. Cook until the wine has reduced by half. Remove half of the shellfish from the pan and set aside, these will be added to the dish when ready to serve. Cover the remaining shellfish with water and cook for a further 10 minutes. Pour the liquid through a sieve to remove the shellfish and shallots and then add the saffron to the stock. De-shell the shellfish and leave to rest in a small amount of stock.
Preheat the oven to 200°C.
Peel the prawns and use the tip of a sharp knife to remove the black spine. Lay the prawns on a baking tray, drizzle with olive oil and then season with salt and the piment d'espelette.
Peel and finely dice the onions. Peel the peppers and cut into strips. Cut the chorizo into pieces.
Heat a large pan and add a drizzle of olive oil. Add the onions to the pan, season with salt and cook for 1 minute. Add the chorizo and the pepper to the pan and cook for a further minute. Add the pasta and the turmeric to the pan and stir in. Add the shellfish stock to the pan a ladleful at a tim. Stir the pasta continually until the stock is absorbed by the pasta and repaeat this process until the pasta is almost cooked. Add the peas and the de-shelled shellfish to the pan and allow to warm through. Check the seasoning.
Whist the pasta is cooking transfer the prawns to the oven and cook for 3 minutes.
Serve the pastasotto topped with the king prawns and the shellfish in their shells.
«If possible, soak the shellfish overnight. Rinse thoroughly under running water if not.»