Clean the prawn tails and shell them. Clean the moscardini removing the skin, the eyes and the insides. Wash and dry them, then dry with a clean tea towel, and slice the baby octopuses and a few prawns into pieces. Peel the onion and slice it finely.Blanch the tomatoes in boiling water, drain them and remove seeds and skin then dice them. Heat a dash of oil in a pan, add the onion and the peeled and softly crushed garlic fry until soft but not golden.Add the tomatoes and cook them over a high heat for 5 minutes stirring with a wooden spoon; remove the garlic. Add the moscardini and the prawns, season with salt and a grind of pepper and simmer for 5 minutes.Before removing the saucepan from the heat, season with the rinsed and chopped parsley. In the meanwhile cook the pasta in a large pan with plenty of boiling salted water. Drain it al dente, arrange it on a serving dish, dress it with the prawn ragù and moscardini and serve nice and warm.