In a medium bowl combine olive oil, juice and zest from 1 lemon, 1/4 teaspoon salt and pinch of pepper. Pour into a resalable bag and place salmon in the bag. Reseal and place in the refrigerator for 15-20 minutes.
In a small bowl, combine sour cream, yogurt, evaporated milk, dill, chives, parsley, 1 tablespoon lemon juice, 1/4 teaspoon salt, 1/8 teaspoon black pepper and shallot. Place in refrigerator until ready to serve.
Spray grill with grilling spray. Turn grill to medium heat.
Remove salmon from bag and discard marinade. Place salmon on grill.
Grill, covered, 5 minutes per side or until fish begins to flake.
Remove from grill and serve with creamy herb sauce.