Spray 10-inch nonstick skillet with cooking spray. Add pork and onion; cook over medium heat 7 to 10 minutes or until no longer pink, stirring frequently.
Stir in taco seasoning mix and 3/4 cup salsa. Cook 2 to 3 minutes or until thoroughly heated and sauce is of desired consistency, stirring occasionally.
In large bowl, combine dressing ingredients; blend well. Add meat mixture, lettuce, broken chips and tomatoes; toss to mix. Spoon onto individual serving plates. Sprinkle salads with cheese. Garnish as desired.