Place popped popcorn in a large bowl. Combine chocolate chips and shortening in a microwave-safe bowl. Heat on 50% power in 30-second intervals until melted, stirring in between each round.
Drizzle the melted chocolate over the popcorn and toss in about ⅓ of the M&M’s. Mix until the popcorn is evenly coated with the chocolate. Continue adding more M&M’s as you mix. The chocolate will cool, and the M&M’s will stick to the popcorn instead of sinking to the bottom of the bowl if you mix them in increments.
Preparation time: 3-5 minutes. Cooking time: 3-5 minute(s).