It's a brine and is suppose to be tossed. But for me personally I add it right in with everything else. I get the corned beef without the packet it's cheaper lol. But here is the recipe for pickling spice.
2 cinnamon sticks
10 bay leaves
2 small dried red hot chiles
5 star anise
4 Tbsp Mustard
seeds2 Tbsp Ground ginger
2 Tbsp Allspice berries
2 tsp Cloves
2 Tbsp Black Peppercorns
2 Tbsp Coriander
seeds2 tsp Cardamom
seeds2 Tbsp dill
seedsBreak the cinnamon stick, bay leaves, chiles, and star anise into pieces.
Roughly chop all the other ingredients, leaving most of the
seeds whole.
Combine and store in a tightly sealed jar for several months.
For the corned beef use about 1 Tablespoon of this pickling spice for the best flavor. I also don't believe that it's corned beef unless it's cooked with cabbage but that's just because I grew up that way lol.