In a large bowl mix all together, soy sauce, vinegar, garlic and onions. Cut chicken into small pieces and then add it into the sauce mixture. Do not add the red pepper yet.
Marinate the chicken for at least 30 minutes to an hour.
Over medium heat add in marinate chicken into a large pot. Cook for an hour or until chicken is tender. If the chicken is still tough add water if need. Add red hot pepper and simmer for at least 10 minutes.