In a large resealable plastic bag, combine 2 tablespoons salsa and 2 tablespoons salad dressing; add the chicken. Seal bag and turn to coat; refrigerate for at least 2 hours.
In a small saucepan, combine the remaining salsa and dressing; cook over low heat until heated through, stirring occasionally; set aside and keep warm.
Drain and discard marinade. Using long-handled tongs, moisten a paper towel with cooking oil and lightly coat the grill rack. Grill chicken, covered, over medium heat or broil 4 in. from the heat for 6-8 minutes on each side or until a meat thermometer reads 170°. Immediately top with cheese. Serve over rice if desired. Top with salsa mixture. Yield: 2 servings.