Cut the pork into bite-sized pieces.
Slice the onion and green onion thinly.
Make the marinade with soy sauce, erythritol, minced garlic, sesame oil, and pepper.
Put the pork and prepared vegetables in a bowl and marinate with the sauce.
Heat oil in a pan and stir-fry the pork and vegetables over medium heat.
When the pork is cooked, transfer to a plate and serve.