For the collard purée:blanch the collard leaves, cool them in water and ice, dry them, then pacotise them (put them in the paco jet to quickly break them up, blend them and stir them).Freeze the oysters in a 2 x 6 cm patisserie mould.While the pasta is cooking, sautée the sliced garlic, add the anchovy then, when it has broken down, add the fish stock.Drain the pasta when it is still very al dente and finish cooking it in the pan. At the end of cooking add the collard purée, the coollard stalks and stir. PRESENTATIONArrange the pasta on a dinner plate. Grate the frozen oysters (with the Microplane) and with the aid of a "pan licker" spread all the sauce that is still in the pan. Add the stalks, the sultanas and sea urchins then serve.