Rinse fresh salmon; pat dry. Set aside. In a large saucepan heat oil over medium-high heat. Cook and stir carrots, onion, and celery in hot oil about 10 minutes or until the vegetables are tender, stirring occasionally.
Meanwhile, to poach fresh salmon, in a large skillet bring water to boiling. Add salmon. Return to boiling; reduce heat. Simmer, covered, for 6 to 8 minutes or until the salmon flakes easily with a fork. Remove salmon from skillet, discarding poaching liquid. Flake salmon into 1/2-inch pieces; set aside.
Stir the broth, potatoes, corn, dill, and salt into vegetables in saucepan. Bring to boiling; reduce heat. Cook, covered, over medium-low heat about 15 minutes or until the potatoes are tender, stirring occasionally.
Stir together 1/2 cup of the milk and cornstarch. Add milk mixture to saucepan. Stir in remaining milk. Cook and stir over medium heat until thickened and bubbly. Cook and stir for 2 minutes more. Gently stir in poached salmon or canned salmon. Heat through.