Fatback and Heirloom Bean Soup

Name: Fatback and Heirloom Bean Soup
Ingredients: 10 oz. skinless pork fatback, rinsed in cold water, and cut into 1” pieces; 12 cups chicken stock; 1 tbsp. kosher salt, plus more to taste; 1 tsp. Accent flavor enhancer; 1 tsp. crushed red chili flakes; 1⁄2 tsp. freshly ground black pepper; 4 carrots, minced; 4 stalks celery, minced; 2 large Vidalia onions, thinly sliced; 2 fresh or dried bay leaves; 1 lb. dried Mother Stallard or pinto beans, soaked overnight and drained; 2 tbsp. apple cider vinegar; 2 scallions, thinly sliced