Sauté chicken in 1 tablespoon hot olive oil in a medium skillet 5 to 6 minutes or until done.
Whisk together vinegar and mustard in a small bowl. Gradually whisk in 6 tablespoons olive oil until smooth. Season with salt and pepper to taste.
Cook pasta according to package directions; drain. Spread pasta in a single layer on a baking sheet. Drizzle with remaining 1 tablespoon olive oil. Let cool 10 minutes.
Toss together pasta, chicken, vinegar mixture, spinach, and remaining 3 ingredients in a large bowl. Season with salt and pepper to taste. Serve immediately, or, if desired, cover and chill 1 hour before serving.