Cook tortellini according to package directions. Drain; rinse with cold water., Meanwhile, in a small bowl, combine chicken, onion, oil, garlic, salt and pepper; toss to coat. Heat a large skillet over medium-high heat. Add chicken mixture; cook and stir 4-6 minutes or until chicken is no longer pink. Remove from heat., In a large bowl, combine salad mix, tomatoes, olives, tortellini and chicken mixture. Drizzle with dressing; toss to coat. Sprinkle with cheese and bacon. Serve immediately.