Place parchment paper on a cookie sheet before you prepare the other items. Melt the white chocolate at your preferred method (I use a glass bowl in the microwave for 1.5-2 minutes, stirring in the middle).

As it melts, mix the m&m's and pretzels in another bowl.

Once the chocolate is all melted nicely, pour it into the mix.  Stir.

Spread mix unto parchment paper to cool.  Allow to set for 20 minutes.  To speed up the hardening process, you can place it in the freezer.

Once cooled, break it up and serve.