Heat the butter in a heavy-bottomed pan. Sauté the garlic, onions, and leeks, letting them cook gently for ten minutes. Add the cooking cream and let it simmer.

Cook the fresh pasta according to the package instructions and drain.

Heat the mussels in a preheated pan for three minutes, stirring occasionally. Drain and reserve the cooking liquid.

Stir the cooked pasta and mussel sauce into the sautéed vegetables. Divide the pasta onto plates and top with the mussels.