Line a 10” x15” pan or cookie sheet with wax or parchment paper. Place chocolate chips and shortening in a microwave-safe bowl. Heat at half-power in 30-second increments, stirring between each, until chocolate is melted and smooth.
Spread chocolate in an even layer on the wax or parchment paper. Sprinkle with desired toppings. Place in the fridge to chill until chocolate is hard, then roughly break into pieces. Store in an airtight container in the refrigerator for up to two weeks (ones with cookies or pretzels may get stale sooner). Makes about 12 servings.