In a bowl, mix all ingredients except bread and butter. Toast bread or, to grill, spread one side of each slice with butter. Spoon half the chicken salad onto a slice of toast or bread, butter side down. Top with another piece of toast or bread, butter side up. Repeat. If grilling, place in a skillet on low heat for about 3 to 4 minutes on each side, or until lightly browned. Cut in half.