Heat a cast iron skillet (ideally) over medium high heat on the stovetop. Add peppercorns, coriander, mustard seeds and anise seeds in. Move around and toast for 3 minutes.
Then add bay leaves and red pepper flakes for 30 more seconds, then immediately remove from the heat source.
Pour contents into your spice blender and pulse until as smooth as you'd like.
Immediately use on top of your corned beef brisket and then cook as you'd like. if you want to store for longer pour into an airtight container or jar in a cool place.