Preheat oven to 350 degrees F (175 degrees C). Lightly grease an 8x8-inch baking dish with olive oil.

Pour 1/4 cup olive oil in a shallow bowl and dip salmon steaks in oil to coat. Stir garlic salt, onion salt, paprika, black pepper, and salt together in a small bowl; sprinkle seasoning onto salmon.

Place salmon steaks into the prepared baking dish and sprinkle with chives, thyme, and spinach leaves. Sprinkle Parmesan cheese over the fish and seasonings.

Bake in the preheated oven until the salmon is cooked through and the flesh flakes easily, about 45 minutes.