To begin making, place the onion and garlic into a slow cooker.
Then, place the brisket over top, fat side up.
Next, in a small bowl, whisk together the Dale’s seasoning, beef broth, black pepper, cumin, chili powder, honey, and dried oregano.
Pour over the brisket, into the slow-cooker.
Then, cover and cook on LOW 8-9 hours or until brisket is fork-tender.
Meanwhile, in a small saucepan combine the red wine vinegar, ¾ cup water, sugar, salt, dried chile and black peppercorns (if using).
Bring just to a boil and whisk well to dissolve the sugar and salt.
Add the onions and let cook for 2 minutes.
Remove from heat and pour the mixture into a glass jar.
Finally, cover and refrigerate until ready to use.