Preheat oven to 400°F (200°C).

Spray a 13x9x2 inch rectangular baking dish with cooking spray.

In the baking dish, sprinkle the thawed and drained asparagus, sliced green onions, 1 1/2 cups of shredded Swiss cheese, and flaked salmon.

In a separate bowl, stir together the Bisquick baking mix, milk, chopped fresh basil (or dried basil), pepper, and eggs until well blended.

Pour the Bisquick mixture evenly over the ingredients in the baking dish.

Bake in the preheated oven for 40 to 45 minutes, or until a knife inserted into the center comes out clean.

Sprinkle the remaining 1 1/2 cups of Swiss cheese over the bake.

Bake for an additional 2 minutes, or until the cheese is melted and bubbly.

Let the bake cool for 5 minutes before cutting and serving.