Cut or tear the leaves away from the thick steams and discard the stems. Leave the small or thin stems. (We prefer it without the thick stems, but you can keep them if that's how you like it. You do you).
Roll the leaves up and slice into smaller strips, or tear with your hands.
Clean out your kitchen sink (or a large bowl) and fill with cold water. Add the ½ cup of vinegar. Place collards in the sink and swish around. Let sit for 10 minutes.
Drain and rinse collards. Repeat the process if necessary. Set the collards aside on paper towels or a clean dish towel until ready to use.
Make Them Greens
Heat a tall cooking pot over medium heat. Add oil. Once hot, add onion. Cook until translucent, about 5 minutes.
Add garlic and cook for 1 minute. Season with black pepper and red pepper flakes. (Do not salt. The smoked turkey is already salty and you can add salt, if necessary, at the end).
Add in enough collards so it fills your pot, about half. Stir frequently and cook until they've cooked down some to allow you to add the rest of the greens.
With all the greens in the pot and cooked down some, add you broth and the smoked turkey leg. Bring the broth to a simmer and turn the heat to low. Cover and simmer for 1 hour.
Use a wooden spoon to break off the turkey away from the bone and break into smaller pieces, or remove from the pot and shred. Add 2 tbsp white vinegar. Stir and simmer for 5 more minutes. Taste and add salt if needed.