Place the oxtails, diced onions, and minced garlic into a large pot.
Pour 8 cups of water into the pot, then place the pot over high heat.
Let boil for about 45 minutes, then turn the heat down to medium high.
Start adding in the collard greens.
Once all of the collard greens are in the pot, start adding in the seasonings, brown sugar, and vinegar.
Pour the remaining 2 cup of water into the pot, and give everything a nice stir, and place a the lid on your pot.
Reduce the heat to medium, and let the greens cook for 1 hour and 20 minutes.
Start adding in the sliced cabbage, then stir in. Cook for another 15-30 minutes (depending on how well you like your cabbage cooked)
Serve and enjoy with cornbread!