In a saucepan over medium heat, add the vinegar, bay leaves, carom seeds, peppercorns and sugar.
Bring this to a boil and then turn down the heat. Let it simmer for 5 minutes.
Pack the shredded cabbage into a clean mason jar.
Pour the hot brine over it and let it sit for 10-15 minutes. Use a clean spoon to pack the red cabbage in.
Cover and refrigerate.
Notes
Make sure you pat dry the cabbage and remove all moisture from its surface before you use it to make the quick pickle.
Use a sharp knife or a mandolin slicer to shred the cabbage. The thinner the cabbage, the quicker it will pickle.
Allow the cabbage to rest in the pickling liquid for at least a few hours, ideally overnight to soak up all the flavors and soften a bit. I did the same when I made my Persian Torshi and curry pickled cauliflower.
Make sure there is enough pickling liquid to cover the red cabbage completely. This helps prevent spoilage.