Line a 15x10x1-in. pan with foil; set aside. In a microwave-safe bowl, melt chips and candy coating; stir until smooth. Stir in the cherries and pistachios. Spread into prepared pan. Refrigerate for 20 minutes.
Using a sharp knife, score surface of candy, making diamond shapes about 1/8 in. deep. Refrigerate 40 minutes longer or until set.
Cut along scored lines into diamonds. Store in an airtight container in the refrigerator.