Rinse the collard greens thoroughly and remove the tough stems. Chop the greens into bite-sized pieces.

Finely chop the onion and mince the garlic.

In a large pot, heat the olive oil over medium heat. Add the chopped onion and cook until translucent, about 5 minutes.

Add the minced garlic and cook for another minute.

Place the smoked ham hock in the pot and pour in the chicken broth. Bring to a boil.

Reduce the heat to low and simmer for 1 hour, or until the ham hock is tender and flavors have melded together.

Add the chopped collard greens to the pot, along with apple cider vinegar, and season with salt, black pepper, and red pepper flakes to taste.

Continue to simmer for another 45 minutes to 1 hour, until the collard greens are tender.

Remove the ham hock, shred the meat, and return it to the pot, discarding the bone.

Adjust seasoning if necessary and serve hot.