01 - Heat olive oil or bacon drippings in a large pot over medium heat. Add diced onion and cook 4-5 minutes until translucent and fragrant.
02 - Stir in minced garlic and cook for 1 minute until aromatic, being careful not to brown or burn.
03 - Add smoked turkey leg or ham hock if using, then pour in chicken broth. Bring mixture to a gentle simmer.
04 - Add chopped collard greens in batches, stirring until each batch wilts and reduces in volume before adding more.
05 - Stir in salt, black pepper, and red pepper flakes if desired. Reduce heat to low, cover, and simmer for 1 hour, stirring occasionally, until greens are completely tender.
06 - Remove meat bones, shred any remaining meat, and return to pot. Stir in apple cider vinegar. Adjust seasoning to taste and serve warm.