Cook bacon in a large pot or Dutch oven over medium heat until crispy, about 5-7 minutes. Remove bacon and set aside, leaving the fat in the pot. (4 slices bacon, chopped)
Add onion to the bacon fat and cook until softened, about 4-5 minutes. Add garlic and red pepper flakes, stir for 30 seconds. (1 small onion diced, 3 cloves garlic minced, pinch red pepper flakes)
Add turnip greens in batches, stirring until wilted enough to fit in the pot. (1.5 lbs turnip greens, stems removed, roughly chopped)
Pour in chicken broth, season with salt and pepper. Bring to a simmer, cover, and cook 20-25 minutes until greens are tender. (1 cup chicken broth, salt, pepper)
Stir in apple cider vinegar and reserved bacon. Taste and adjust seasoning. (1 tbsp apple cider vinegar)
