Drain the salmon, rinse it in cold water and carefully remove any bones. Flake it coarsely, then set aside. In a large skillet, saut the green onion in oil, stirring often. In a small bowl, whisk together cornstarch and two tablespoons of chicken broth until smooth. Whisk in mustard and remaining broth, mixing thoroughly. Pour into the skillet with the green onions, stirring constantly . until mixture thickens. Add heavy cream, dill, lemon juice and salmon. Heat just to serving temperature. - In a serving bowl, pour the sauce over the warm fettucine. Toss gently . and serve immediately.