Slit the membrane of the squill on the lower part and discard it; extract the pulp, rinse and dry it. Peel the garlic and the onion, then cut the garlic in halves and chop the onion finely. Clean the fennel, remove the stalks and slice it into segments, keeping the leaves aside.Blanch the tomatoes in boiling water, peel them, deseed them and, once drained, dice them. Heat 2 tbsp of oil in a pan with the chopped onion and 1/2 clove of garlic and fry until golden, then add the fennel and brown for 1 minute, stirring.Season with salt and pepper, ladle some water over it and simmer for 8-10 minutes over a medium heat. In the meanwhile put the remaining oil in a pan with the leftover garlic and golden lightly. Add the squills to this mixture and brown for a minute. Once evenly golden, season with salt and pepper then add the fennel. Add the tomatoes and simmer for 5-6 minutes. In the meanwhile cook the pasta and drain when al dente.Mix it with the fennel and squill sauce, garnish with a sprinkle of chopped parsley and fennel leaves and serve.