Place pretzels in a food processor and blend until pretzels resemble breadcrumbs.
In a small bowl, combine mustard, honey and egg white. Mix well.
Pour mustard mixture on brussel sprouts, stirring until all halves are coated. Add in pretzel crumbs and mix until all halves are coated in crumbs.
Place brussel sprouts onto a large cooking sheet lined with parchment paper. Drizzle olive oil on top.
Bake for 40 minutes (flipping at 20 minutes), or until brussel sprouts are roasted. It make take less time depending on your oven so watch them carefully!