1. Sprinkle chicken with seasoning mix. Place 1/4 of the potatoes on centre of each of 4 large sheets of heavy-duty foil; top with chicken, cheese and salsa.
2. Fold foil to make 4 packets, leaving room for heat circulation inside. Place on baking sheet.
3. Bake 30 to 35 min. or until chicken is done (170°F). Cool 5 min. Cut slits in foil to release steam before opening packets. Top with sour cream.