Ask your friendly SuperValu fishmonger to peel the prawns for you – just be sure to also ask for them back, as you can use them for the sauce.
1. To make the sauce, place a medium-sized pot over a medium heat. Add the prawn shells and cook for 3 to 4 minutes, then add the chopped onion, tomato purée and water. Bring to the boil and simmer for 10 minutes, then strain through a fine mesh sieve into another clean pot and discard the shells. Add the cream and white wine to the pot and reduce by one-third. Set aside.
2. Cook the pasta in a large pot of boiling salted water according to the packet instructions, until al dente. Drain and keep warm.
3. Heat a large heavy-based frying pan over a medium-high heat. Add the oil and allow it to get quite hot. Cook the peeled prawns and chunks of sea trout for 2 to 3 minutes. Add the sauce to the frying pan, then the baby spinach. Fold in the pasta.
4. Serve in a large bowl, garnish with parsley and place in the centre of the table to let everyone help themselves.