Place a skillet over high heat and and add low sodium chicken broth. Bring to boil and add ground chicken. Stir continuously to prevent lumps. Cook until chicken is browned or cooked through about 6 minutes.
Remove chicken and set aside.
Mix fish sauce, fresh lime juice, sugar, red onions and lemongrass in a mixing bowl, then add cooked ground chicken. Stir until well-mixed.
Stir in fresh mint leaves and cilantro right before serving and spoon the mixture into the cabbage to serve.
Notes
I advise to use Thai fish sauce as it has about half the salt of Vietnamese fish sauce.