Rinse and clean mussels and lobsters (either spiny or clawed lobsters can be used). Boil in water in a large pot until lobsters turn bright pink and mussels are firm and white. Remove and run cold water over shells to cool. Reserve stock (including mussels and shells). Remove meat from body and claws of the lobster, including tomalley and any roe, and chop coarsely. Remove membrane from each tail and separate meat from shell with a knife. Saute vegetables in oil. Add tomato paste, wine, stock, spices, and empty lobster body/claw shells (for added flavor) and simmer until reduced and thickened (at least two hours). Add stock as needed to thin. Remove shells from simmering sauce. Add lobster meat to sauce and simmer for another 10 minutes. Add cream, stir, and remove from heat. Fill each lobster tail with a generous amount of sauce. Toss pasta in butter and place on a large serving platter. Spoon remaining sauce over and top with claws and optional mussels. Serve with green salad, crusty bread, and wine. Serves six.