Cut the chicken breast into bite-sized pieces.
Dice the bell pepper and onion.
Add olive oil to a pan and stir-fry the chicken breast.
When the chicken is cooked, add the bell pepper and onion and stir-fry together.
Add soy sauce, vinegar, erythritol, and minced garlic, then quickly stir-fry over high heat.
Season with black pepper to taste and finish.