Prepare pasta according to package directions.
Meanwhile, brush 1 tablespoon olive oil on salmon. Sprinkle with slat and pepper. Heat an extra-large skillet over medium heat; add salmon. Cook 8 to 12 minutes or until salmon flakes, turning once. Remove salmon; cover and keep warm. Add spinach, sweet peppers, and remaining oil to skillet. Cook and stir 1 to 2 minutes, until spinach is wilted. Drain pasta; add to skillet. Add dressing; toss to coat. Season with salt and pepper. Divide spinach-pasta mixture among four bowls. Top with salmon. Serves 4.