Ensuring that the meat is covered in the marinade.Leave to marinate in the fridge for at least 2 hours, or overnight for best results.In a large saucepan, placed over medium heat, place the coconut oil, onion and garlic and saute for 5-7 minutes.Add the marinated pork and cook for 5-7 minutes, until the pork had colored.Add the diced tomatoes, Serrano Chilies, water and erythritol (if using).Bring to a simmer and continue to cook for 60-90 minutes, until the pork is tender.Serve and enjoy.