Sprinkle chicken pieces with salt. Cut
potato lengthwise into 1/8" slices; cut zucchini into 1/4" slices. Layer
1/2 of potatoes, salt, zucchini and salt on 18"x12" piece of double
thickness heavy-duty aluminum foil. Top with 1/2 of the chicken, olives,
tomato sauce and oregano; dot with butter. Wrap securely in foil. Repeat
for other serving. Place on grill 5" from medium coals. Cook 25 to 30
minutes on each side or until chicken and vegetables are tender.