Heat a large stockpot over medium heat. Add bacon; cook 8 minutes, stirring occasionally. Add onion and garlic; sauté 5 minutes. Stir in greens, chicken stock and 2 cups water; bring to a boil. Cover and reduce heat to medium-low; cook 20 minutes. Uncover and cook 25 minutes. Stir in salt.
Using tongs, remove greens to a serving bowl, allowing excess liquid to drip off.