Step 1

Line a large baking sheet with parchment paper or wax paper; set aside.

Step 2

In a very large bowl, mix together the Rice Chex, Cheerios, peanuts, pretzels and M&Ms.

Step 3

In a medium bowl, melt the white chocolate and shortening in the microwave on 50% power, stirring every 30 seconds, until completely melted.

Step 4

Pour the melted chocolate over the dry ingredients and quickly toss together until everything is pretty evenly coated in the white chocolate. Spread the mixture out on the prepared pan and refrigerate until it's set, about 20 minutes. Break up any chunks and store in tins or airtight containers in the refrigerator for up to 4 weeks.