Saute in shrimp butter. Cook the pasta in a 4-quart pot of boiling water, adding the salt and oil. Cook a few minutes or until the pasta is al dente. (The pasta will continue to cook as you make the sauce, so don't overcook.) Drain. Heat an 11" saucepan. Add the butter, shallots and garlic. Cook until translucent. Add shrimp and scallops and simmer for one minute. Add cream. Reduce heat to simmer. Add pasta and salt and pepper to taste. Cook, tossing occasionally, until shellfish and pasta are al dente. Garnish with parsley and serve. NOTE: If using fresh fettuccine, cook only one to two minutes. Packaged noodles may take eight to twelve minutes. The starch from the pasta helps to bind this delicious sauce. May be served as an entree.