Microwave cherries and 2 tablespoons water in a small glass bowl at HIGH 2 minutes; drain.
Melt chocolate and candy coating in a heavy saucepan over low heat. Remove from heat; stir in cherries and pistachios. Spread into a wax paper-lined 15- x 10-inch jellyroll pan.
Chill 1 hour or until firm. Cut with a 3-inch heart-shaped cookie cutter. Store in airtight container.