Dill sauced salmon

1 salmon fillet (about 2 pounds)
1 to 1-1/2 teaspoons lemon-pepper seasoning
1 teaspoon onion salt
1 small onion, sliced and separated into rings
6 lemon slices
1/4 cup butter

DILL SAUCE:
1/3 cup sour cream
1/3 cup mayonnaise
1 tablespoon finely chopped onion
1 teaspoon lemon juice
1 teaspoon prepared horseradish
3/4 teaspoon dill weed
1/4 teaspoon garlic salt
Pepper to taste
Directions
Line a 15-in. x 10-in. x 1-in. baking pan with heavy-duty foil; grease lightly. Place salmon skin side down on foil. Sprinkle with lemon-pepper and onion salt. Top with onion and lemon. Dot with butter. Fold foil around salmon; seal tightly,
Bake at 350° for 20 minutes. Open foil. Broil 4-6 in. from the heat for 8-12 minutes or until the fish flakes easily with a fork.
Combine the sauce ingredients until smooth. Serve with salmon. Yield: 6 servings.