In a small bowl, combine the lime juice, oil, garlic salt and pepper. Set aside 5 tablespoons. Pour remaining lime juice mixture into a resealable plastic bag; add chicken. Seal and turn to coat; let stand at room temperature for 10 minutes.
Meanwhile, in a small bowl, combine the corn, tomato, pepper, green onion, cumin and 3 tablespoons reserved lime juice mixture. Cover and refrigerate.
Drain and discard marinade from chicken. Using long-handled tongs, moisten a paper towel with cooking oil and lightly coat the grill rack. Grill, covered, over medium heat or broil 4 in. from heat for 5-6 minutes on each side or until a meat thermometer reads 170°, basting twice with remaining lime juice mixture.
Top with cheese; grill or broil 1-2 minutes longer or until cheese is melted. Serve with salsa. Yield: 4 servings.