1. Bring pot of salted water to boil.
2. Meanwhile, whisk lemon juice, sugar, shallot, 1/2 teaspoon salt, 1/4 teaspoon pepper, mustard and oil in small bowl.
3. Transfer 1/4 cup dressing to plastic food bag or glass dish; add turkey; turn to coat. Marinate 15 minutes. Reserve remaining dressing.
4. Add tortellini to boiling water; cook according to package directions. Drain; rinse; drain.
5. Prepare outdoor grill with medium-hot coals, or heat gas grill to medium-hot, or heat oven broiler.
6. Combine cherry tomatoes and spinach in large serving bowl.
7. Remove turkey from marinade; discard marinade. Grill or broil cutlets 6 inches from heat, 5 minutes per side depending on thickness, or until internal temperature registers 170 degrees F. Cut turkey into bite-size pieces.
8. Add drained pasta to mixture in bowl. Add turkey, reserved dressing and walnuts; toss to mix. Serve slightly warm or chilled.