Heat gas or charcoal grill. Spray grill basket (grill "wok") with nonstick cooking spray. In medium bowl, combine bell pepper and onion stir-fry, oil and seasoned salt; toss to coat. Place in sprayed grill basket. Wrap tortillas securely in heavy-duty foil.
When grill is heated, place grill basket on gas grill over medium heat or on charcoal grill 4 to 6 inches from medium coals. Cook bell pepper mixture 5 minutes, shaking basket occasionally to mix.
Place packet of tortillas next to grill basket on grill. Add thawed chicken strips to bell pepper mixture; cook an additional 5 to 8 minutes or until chicken is thoroughly heated and vegetables are crisp-tender, shaking basket occasionally to mix.
Spread warm tortillas with guacamole. Top each with about 3/4 cup chicken mixture; roll up. Serve with salsa.